Morgagni-Stewart-Morel Syndrome

Complex MONDO:0007766 Pathograph 14 Metabolic bone disease Endocrine disorder

Morgagni-Stewart-Morel syndrome is a rare condition characterized by the triad of hyperostosis frontalis interna (thickening of the inner table of the frontal bone), obesity, and neuropsychiatric disturbances. Additional features include endocrine disorders such as diabetes mellitus, diabetes insipidus, hyperparathyroidism, hyperprolactinemia, hirsutism, and menstrual irregularities. The syndrome predominantly affects postmenopausal women, with a female-to-male ratio of approximately 9:1. The etiology remains incompletely understood but is thought to involve endocrine imbalance driven by genetic and environmental factors, with prolonged estrogen exposure, elevated leptin levels, and growth hormone dysregulation implicated in the pathogenesis of the skull thickening.

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1
Mappings
1
Inheritance
4
Pathophys.
12
Phenotypes
14
Pathograph
1
Genes
4
Medical Actions
3
Differentials
5
References
1
Deep Research
🏷

Classifications

Harrison's Chapter
IMMUNE_RHEUMATOLOGIC NEUROLOGIC ENDOCRINOLOGY_METABOLISM
🔗

Mappings

ICD-10-CM
ICD10CM:M85.2 Hyperostosis of skull
skos:closeMatch ICD-10-CM MONDO: MISSING
ICD-10-CM M85.2 covers hyperostosis of skull, which encompasses the defining feature of Morgagni-Stewart-Morel syndrome (hyperostosis frontalis interna). No specific ICD-10 code exists for the full syndrome.
👪

Inheritance

1
Autosomal dominant HP:0000006
Multiple-generation family studies and monozygotic twin concordance suggest autosomal dominant inheritance with incomplete penetrance and variable expressivity. Hyperostosis frontalis interna has been found in multiple generations of affected families, though no case of male-to-male transmission has been documented, and X-linked dominant inheritance has not been excluded.
Autosomal dominant inheritance Penetrance: INCOMPLETE Expressivity: VARIABLE
Show evidence (2 references)
PMID:16909048 SUPPORT Human Clinical
"We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment. They both have suffered from generalized seizures since their early adulthood."
Monozygotic twin concordance for MSM syndrome features strongly supports a genetic basis for the disorder.
PMID:16909048 SUPPORT Human Clinical
"The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
The authors explicitly conclude that the concordance in monozygotic twins indicates a genetic basis for MSM syndrome.
⚙

Pathophysiology

4
Endocrine-mediated calvarial bone overgrowth
The precise pathogenesis of frontal bone thickening remains unclear. Well-supported hypotheses include prolonged estrogen exposure stimulating osteoblastic activity in the frontal bone inner table (supported by large-scale anthropological studies) and elevated leptin levels associated with obesity promoting bone formation. A more contested hypothesis involves dysregulated growth hormone secretion from pituitary microadenomatosis; however, recent evidence shows no direct causative role for GH excess or hyperprolactinemia in HFI etiopathogenesis. The condition predominantly affects females and is associated with age, being much less frequent in females under 40 years.
Osteoblast CL:0000062
Bone mineralization GO:0030282 Osteoblast differentiation GO:0001649
Frontal bone UBERON:0000209
Downstream
Hyperostosis frontalis interna
Obesity
Increased intracranial pressure from frontal bone expansion
Show evidence (5 references)
PMID:10407462 SUPPORT Human Clinical
"It is most commonly found among females and is believed to be associated with prolonged estrogen stimulation"
Establishes the estrogen hypothesis for HFI pathogenesis based on a large-scale anthropological study of over 1,700 skulls.
PMID:10407462 SUPPORT Human Clinical
"While its magnitude of manifestation and frequency are much higher in females, HFI is not a purely female phenomenon. Males with hormonal disturbances such as atrophic testis were found to manifest HFI type D."
The association of HFI with hormonal disturbances in males further supports the endocrine-mediated pathogenesis hypothesis.
PMID:36217295 SUPPORT Human Clinical
"It is most often found in women after menopause. It is also associated with hormonal imbalance, being overweight, history of headaches, and neurocognitive degenerative conditions. Female gender, advanced age, extended estrogen stimulation, and elevated leptin levels may also play a role."
Summarizes the leading etiological theories including estrogen, leptin, and hormonal imbalance for HFI development.
+ 2 more references
Neurological compression from calvarial thickening
Progressive thickening of the frontal bone inner table can lead to compression of underlying brain parenchyma, particularly the frontal lobes. This mechanical compression may result in cerebral atrophy, cognitive impairment, neuropsychiatric symptoms including depression and anxiety, headaches, seizures, and cranial nerve dysfunction affecting olfaction and vision.
Neuron CL:0000540
Neuron apoptotic process GO:0051402
Frontal cortex UBERON:0001870
Downstream
Cognitive impairment
Depression
Seizures
Increased intracranial pressure from frontal bone expansion
Vertigo
Show evidence (3 references)
PMID:27428347 SUPPORT Human Clinical
"In she were performed imaging of the skull where was observed the presence of extensive hyperostosis frontalis interna, cortical atrophy and a left thalamic lacunar infarction."
Imaging findings demonstrate the association between HFI and cortical atrophy in a patient with MSM syndrome.
PMID:25382447 SUPPORT Human Clinical
"In 1928 Stewart and in 1930 Morel added neuropsychiatric symptoms, e.g. depression and dementia, which led to the definition of the Morgagni-Stewart-Morel Syndrome (MSM)."
Establishes the historical association between HFI and neuropsychiatric symptoms including depression and dementia as core features of MSM.
PMID:23284007 SUPPORT Human Clinical
"the severity of our patient's neurological and psychiatric symptoms correlates well with the severity of her hyperostosis frontalis interna and the cortical atrophy."
Demonstrates dose-response relationship between HFI severity and neuropsychiatric symptom severity, supporting mechanical compression.
Hyperprolactinemia-associated endocrine dysfunction
Hyperostosis frontalis interna is strongly associated with acromegaly and hyperprolactinemia, particularly when both conditions coexist. Elevated prolactin levels may contribute to menstrual disturbances, galactorrhea, and hirsutism observed in MSM syndrome. The relationship between HFI and hyperprolactinemia appears to be particularly strong in acromegalic patients.
Mammotroph CL:0002311
Prolactin secretion GO:0070459
Anterior pituitary gland UBERON:0002196
Downstream
Amenorrhea
Galactorrhea
Hirsutism
Show evidence (3 references)
PMID:2349162 SUPPORT Human Clinical
"Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
Demonstrates a highly significant association between hyperprolactinemia and HFI in acromegalic patients.
PMID:2349162 SUPPORT Human Clinical
"The cause of HFI remains unknown but appears to be strongly associated with acromegaly, particularly in the presence of co-existent hyperprolactinaemia."
Supports the association between HFI and hyperprolactinemia as a contributing pathway in MSM syndrome.
PMID:36223065 PARTIAL Human Clinical
"There was no difference between the HFI positive and negative acromegalic patients in basal GH, IGF-1, and PRL levels, IGF-1 index, diagnosis lag time, and insulin resistance."
A more recent study found no difference in prolactin levels between HFI-positive and HFI-negative acromegalic patients, suggesting the relationship may be indirect.
Increased intracranial pressure from frontal bone expansion
Progressive frontal bone thickening can result in increased intracranial pressure due to reduced intracranial volume and potential obstruction of CSF flow pathways. This increased pressure may contribute to headaches and other neurological symptoms observed in MSM syndrome. The mechanism links the skeletal abnormality (hyperostosis) to neurological manifestations through biomechanical effects.
Regulation of body fluid levels GO:0050878
Cranial cavity UBERON:0013411
Downstream
Headache
Show evidence (2 references)
PMID:36217295 SUPPORT Human Clinical
"It is most often found in women after menopause. It is also associated with hormonal imbalance, being overweight, history of headaches, and neurocognitive degenerative conditions."
Establishes the association between HFI and headaches in affected individuals, supporting the increased ICP hypothesis.
PMID:27428347 SUPPORT Human Clinical
"In she were performed imaging of the skull where was observed the presence of extensive hyperostosis frontalis interna, cortical atrophy and a left thalamic lacunar infarction."
The imaging findings of cortical atrophy in conjunction with extensive HFI support the hypothesis of increased intracranial pressure effects.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Morgagni-Stewart-Morel Syndrome Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

12
Breast 1
Galactorrhea HP_0040284 Galactorrhea HP:0100829
Show evidence (1 reference)
PMID:2349162 SUPPORT Human Clinical
"The cause of HFI remains unknown but appears to be strongly associated with acromegaly, particularly in the presence of co-existent hyperprolactinaemia."
Hyperprolactinemia is strongly associated with HFI. Galactorrhea is a direct clinical manifestation of hyperprolactinemia.
Ear 1
Vertigo HP_0040283 Vertigo HP:0002321
Show evidence (1 reference)
PMID:27428347 SUPPORT Human Clinical
"A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
Dizziness documented as part of the clinical presentation in a case of MSM syndrome.
Endocrine 2
Diabetes mellitus HP_0040283 Diabetes mellitus HP:0000819
Show evidence (3 references)
PMID:27428347 SUPPORT Human Clinical
"A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
Type 2 diabetes mellitus is documented as a comorbidity in this MSM syndrome case report.
PMID:27428347 SUPPORT Human Clinical
"During this hospital stay the presence of grade I obesity, hyperglycemia, hypertriglyceridemia and hyperuricemia was documented."
Hyperglycemia and metabolic disturbances are documented features of MSM syndrome.
PMID:23284007 SUPPORT Human Clinical
"Metabolic and endocrine dysfunctions should be interpreted not only as isolated components of the syndrome, but also as the reason behind its pathogenesis."
Metabolic dysfunctions including glucose dysregulation are considered integral components of MSM syndrome.
Diabetes insipidus HP_0040284 Diabetes insipidus HP:0000873
Diabetes insipidus was reported in association with metabolic craniopathy (hyperostosis frontalis interna) by Dann (1951, Ann Intern Med 34:163-202, PMID:14790546), but this early report predates modern abstract indexing and no quotable abstract is available. A 1963 Russian-language review (PMID:14149113) also lists diabetes insipidus among hypothalamic-pituitary syndromes including HFI. The association remains poorly documented in the modern literature with no recent case series providing quantitative data.
Genitourinary 1
Amenorrhea HP_0040283 Amenorrhea HP:0000141
Show evidence (1 reference)
PMID:2349162 SUPPORT Human Clinical
"Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
Hyperprolactinemia is strongly associated with HFI, and amenorrhea is a well-established consequence of hyperprolactinemia.
Head and Neck 1
Hyperostosis frontalis interna HP_0040281 Hyperostosis frontalis interna HP:0004438
Show evidence (3 references)
PMID:36484746 SUPPORT Human Clinical
"Hyperostosis frontalis interna was first described in 1719 in association with obesity and hirsutism, forming Morgagni's syndrome."
Confirms hyperostosis frontalis interna as the defining feature of the syndrome, historically described from its first report.
PMID:10407462 SUPPORT Human Clinical
"Hyperostosis frontalis interna (HFI) is manifested by the accretion of bone on the inner table of the frontal bone."
Defines HFI as bone accretion on the inner table of the frontal bone, consistent with the phenotype description.
PMID:36484746 SUPPORT Human Clinical
"The anomaly exclusively involves the inner table and constantly spares the diploe and the external table."
Specifies that HFI exclusively affects the inner table, sparing the diploe and external table.
Integument 1
Hirsutism HP_0040283 Hirsutism HP:0001007
Show evidence (2 references)
PMID:36484746 SUPPORT Human Clinical
"Hyperostosis frontalis interna was first described in 1719 in association with obesity and hirsutism, forming Morgagni's syndrome."
Hirsutism was one of the original features described by Morgagni in 1719 alongside HFI and obesity.
PMID:36452994 SUPPORT Human Clinical
"Morgagni-Stewart-Morel (MSM) syndrome is characterized by the thickening of the frontal bone of the skull (hyperostosis frontalis interna) obesity, neurological symptoms, and hypertrichosis."
Hypertrichosis (hirsutism) is listed as a defining feature of MSM syndrome.
Nervous System 4
Headache HP_0040282 Headache HP:0002315
Show evidence (2 references)
PMID:36452994 SUPPORT Human Clinical
"We present the case of a 76-year-old patient who complained of confusion, extreme irritability, and headache and was diagnosed with MSM based on examination, imaging, and test results."
Headache is documented as a presenting symptom in this case of MSM syndrome.
PMID:23284007 SUPPORT Human Clinical
"A 75-year-old woman presented with severe frontal headache and a history of psychotic disorders."
Severe frontal headache was the presenting symptom in this case of full-penetrance MSM syndrome.
Seizures HP_0040283 Seizure HP:0001250
Show evidence (1 reference)
PMID:16909048 SUPPORT Human Clinical
"They both have suffered from generalized seizures since their early adulthood."
Both monozygotic twins with MSM syndrome had generalized seizures since early adulthood, supporting seizures as a feature of the syndrome.
Cognitive impairment HP_0040283 Cognitive impairment HP:0100543
Show evidence (2 references)
PMID:16909048 SUPPORT Human Clinical
"We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment."
Cognitive impairment is documented in both twins with MSM syndrome.
PMID:27428347 SUPPORT Human Clinical
"A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
Cognitive impairment is part of the clinical presentation in this case of MSM syndrome.
Depression HP_0040283 Depression HP:0000716
Show evidence (2 references)
PMID:25382447 SUPPORT Human Clinical
"In 1928 Stewart and in 1930 Morel added neuropsychiatric symptoms, e.g. depression and dementia, which led to the definition of the Morgagni-Stewart-Morel Syndrome (MSM)."
Depression is one of the classic neuropsychiatric features that helped define MSM syndrome.
PMID:16909048 SUPPORT Human Clinical
"Moreover, the patients showed some additional conditions only occurring in one individual or the other such as migraine, marked recurrent depressive disorder or polyarthrosis."
Recurrent depressive disorder documented in one of the monozygotic twins with MSM syndrome.
Growth 1
Obesity HP_0040282 Obesity HP:0001513
Show evidence (3 references)
PMID:16909048 SUPPORT Human Clinical
"We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment."
Obesity is documented as a core feature in this twin case report of MSM syndrome.
PMID:27428347 SUPPORT Human Clinical
"During this hospital stay the presence of grade I obesity, hyperglycemia, hypertriglyceridemia and hyperuricemia was documented."
Obesity and metabolic disturbances documented in a clinical case of MSM syndrome.
PMID:36452994 SUPPORT Human Clinical
"Morgagni-Stewart-Morel (MSM) syndrome is characterized by the thickening of the frontal bone of the skull (hyperostosis frontalis interna) obesity, neurological symptoms, and hypertrichosis."
Obesity is listed as a defining feature of MSM syndrome.
🧬

Genetic Associations

1
Familial hyperostosis frontalis interna (Susceptibility)
Show evidence (2 references)
PMID:16909048 SUPPORT Human Clinical
"The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
Identical phenotype in monozygotic twins provides strong evidence for a genetic basis of MSM syndrome.
PMID:36223065 SUPPORT Human Clinical
"Various genetic or epigenetic factors may contribute to its etiology."
Supports the hypothesis that genetic or epigenetic factors underlie HFI susceptibility.
💊

Medical Actions

4
Symptomatic headache management
Action: Symptomatic headache management Ontology label: Pharmacotherapy NCIT:C15986
Standard analgesic medications for management of chronic headaches associated with the syndrome.
Show evidence (2 references)
PMID:23284007 SUPPORT Human Clinical
"A 75-year-old woman presented with severe frontal headache and a history of psychotic disorders."
Severe frontal headache is a prominent presenting symptom in MSM syndrome requiring pharmacological management.
PMID:36452994 SUPPORT Human Clinical
"We present the case of a 76-year-old patient who complained of confusion, extreme irritability, and headache and was diagnosed with MSM based on examination, imaging, and test results."
Headache is documented as a presenting complaint requiring symptomatic treatment in MSM.
Antiepileptic therapy
Action: Antiepileptic therapy Ontology label: Pharmacotherapy NCIT:C15986
Standard antiepileptic medications for management of seizures when present.
Show evidence (1 reference)
PMID:16909048 SUPPORT Human Clinical
"They both have suffered from generalized seizures since their early adulthood."
Generalized seizures from early adulthood in MSM patients require ongoing antiepileptic management.
Multidisciplinary management
Action: Multidisciplinary management Ontology label: supportive care MAXO:0000950
Comprehensive care targeting the neurological, endocrine, and metabolic components of the syndrome through coordinated multidisciplinary care.
Show evidence (2 references)
PMID:41229651 SUPPORT Human Clinical
"A multidisciplinary approach targeting the neurological, endocrine, and respiratory components led to progressive clinical improvement and a favourable recovery."
Multidisciplinary management targeting multiple organ systems led to favorable outcomes in an acute MSM case.
PMID:41229651 SUPPORT Human Clinical
"Multidisciplinary collaboration is crucial in managing complex cases of Morgagni-Stewart-Morel syndrome, especially in acute settings where diagnosis is challenging."
Authors emphasize the importance of multidisciplinary collaboration for MSM syndrome management.
Genetic counseling
Action: Genetic counseling Ontology label: genetic counseling MAXO:0000079
Recommended for patients and their families given the evidence for genetic predisposition in the syndrome.
Show evidence (1 reference)
PMID:16909048 SUPPORT Human Clinical
"The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
Evidence for a genetic basis supports the recommendation for genetic counseling in affected families.
🌍

Environmental Factors

1
Prolonged estrogen exposure
exposure to estrogens ECTO:9000010
Extended exposure to endogenous estrogen, as seen in postmenopausal women with a history of obesity, is hypothesized to contribute to the development of hyperostosis frontalis interna through stimulation of osteoblastic activity in the frontal bone.
Show evidence (3 references)
PMID:10407462 SUPPORT Human Clinical
"It is most commonly found among females and is believed to be associated with prolonged estrogen stimulation"
Large-scale anthropological study supports prolonged estrogen stimulation as a contributing factor to HFI development.
PMID:10407462 SUPPORT Human Clinical
"HFI is associated with age insofar as it is much less frequent in females under 40 years of age."
Age-related increase in HFI frequency is consistent with cumulative estrogen exposure as a risk factor.
PMID:36217295 SUPPORT Human Clinical
"Female gender, advanced age, extended estrogen stimulation, and elevated leptin levels may also play a role."
Identifies extended estrogen stimulation as a potential contributing factor for HFI development.
🔬

Biochemical Markers

2
Growth hormone (Elevated)
Context: Basal plasma growth hormone levels slightly increased with failure to suppress after glucose loading
Show evidence (2 references)
PMID:36223065 PARTIAL Human Clinical
"The frequency of HFI was higher in acromegalic patients than in the controls (22%, 0%, and 2.2%, respectively)."
HFI is significantly more frequent in patients with GH excess (acromegaly), though the study found no direct causal role for GH in HFI etiopathogenesis.
PMID:2349162 SUPPORT Human Clinical
"There was a higher prevalence of HFI in the skull X-rays of the acromegalic cohort (P = 0.0002) when compared to the control group."
Highly significant association between acromegaly (GH excess) and HFI prevalence.
Prolactin (Elevated)
Context: Hyperprolactinemia found in patients with hyperostosis frontalis interna and galactorrhea
Show evidence (2 references)
PMID:2349162 SUPPORT Human Clinical
"Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
Highly significant association between hyperprolactinemia and HFI in acromegalic patients.
PMID:36223065 PARTIAL Human Clinical
"There was no difference between the HFI positive and negative acromegalic patients in basal GH, IGF-1, and PRL levels, IGF-1 index, diagnosis lag time, and insulin resistance."
While hyperprolactinemia has been historically associated with MSM, this study found no difference in prolactin levels between HFI-positive and HFI-negative acromegalic patients.
🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from Morgagni-Stewart-Morel Syndrome:

Paget disease of bone Not Yet Curated MONDO:0005382
Distinguishing Features
  • Paget disease involves both inner and outer tables and diploe with characteristic cotton-wool appearance on imaging, unlike HFI which exclusively affects the inner table.
Show evidence (3 references)
PMID:36484746 SUPPORT Human Clinical
"The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
Paget disease is listed as a major differential diagnosis for cranial hyperostosis.
PMID:15228235 SUPPORT Human Clinical
"HFI should be recognized as a benign entity and distinguished from other disorders that involve the frontal skull bone, such as Paget's disease, acromegaly, and malignancy."
Emphasizes the importance of distinguishing HFI from Paget disease and other conditions affecting the frontal skull bone.
PMID:36484746 SUPPORT Human Clinical
"The anomaly exclusively involves the inner table and constantly spares the diploe and the external table."
The key distinguishing feature is that HFI exclusively affects the inner table, while Paget disease involves all layers.
Meningioma MONDO:0016642
Distinguishing Features
  • Meningiomas can cause focal hyperostosis but typically present as a mass lesion with contrast enhancement on imaging, unlike the diffuse bilateral inner table thickening of HFI.
Show evidence (1 reference)
PMID:36484746 SUPPORT Human Clinical
"The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
Meningioma is listed as a major differential diagnosis for cranial hyperostosis.
Fibrous dysplasia MONDO:0000845
Distinguishing Features
  • Fibrous dysplasia involves replacement of normal bone with fibrous tissue and has a ground-glass appearance on imaging, affecting the diploe rather than the inner table exclusively.
Show evidence (1 reference)
PMID:36484746 SUPPORT Human Clinical
"The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
Fibrous dysplasia is listed as a major differential diagnosis for cranial hyperostosis.
{ }

Source YAML

click to show 
name: Morgagni-Stewart-Morel Syndrome
creation_date: '2026-02-09T22:41:02Z'
updated_date: '2026-05-10T12:24:13Z'
category: Complex
description: >
  Morgagni-Stewart-Morel syndrome is a rare condition characterized by the triad of
  hyperostosis frontalis interna (thickening of the inner table of the frontal bone),
  obesity, and neuropsychiatric disturbances. Additional features include endocrine
  disorders such as diabetes mellitus, diabetes insipidus, hyperparathyroidism,
  hyperprolactinemia, hirsutism, and menstrual irregularities. The syndrome predominantly
  affects postmenopausal women, with a female-to-male ratio of approximately 9:1.
  The etiology remains incompletely understood but is thought to involve endocrine
  imbalance driven by genetic and environmental factors, with prolonged estrogen
  exposure, elevated leptin levels, and growth hormone dysregulation implicated in
  the pathogenesis of the skull thickening.
disease_term:
  preferred_term: Morgagni-Stewart-Morel syndrome
  term:
    id: MONDO:0007766
    label: Morgagni-Stewart-Morel syndrome
mappings:
  icd10cm_mappings:
  - term:
      id: ICD10CM:M85.2
      label: Hyperostosis of skull
    mapping_predicate: skos:closeMatch
    mapping_source: ICD-10-CM
    mapping_justification: >
      ICD-10-CM M85.2 covers hyperostosis of skull, which encompasses
      the defining feature of Morgagni-Stewart-Morel syndrome (hyperostosis
      frontalis interna). No specific ICD-10 code exists for the full
      syndrome.
    consistency:
    - reference: MONDO
      consistent: MISSING
parents:
- Metabolic bone disease
- Endocrine disorder
synonyms:
- Hyperostosis frontalis interna
- Morgagni syndrome
- Stewart-Morel syndrome
- Metabolic craniopathy
inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  penetrance: INCOMPLETE
  expressivity: VARIABLE
  description: >
    Multiple-generation family studies and monozygotic twin concordance suggest
    autosomal dominant inheritance with incomplete penetrance and variable
    expressivity. Hyperostosis frontalis interna has been found in multiple
    generations of affected families, though no case of male-to-male transmission
    has been documented, and X-linked dominant inheritance has not been excluded.
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment. They both have suffered from generalized seizures since their early adulthood."
    explanation: Monozygotic twin concordance for MSM syndrome features strongly supports a genetic basis for the disorder.
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
    explanation: The authors explicitly conclude that the concordance in monozygotic twins indicates a genetic basis for MSM syndrome.
pathophysiology:
- name: Endocrine-mediated calvarial bone overgrowth
  description: >
    The precise pathogenesis of frontal bone thickening remains unclear. Well-supported
    hypotheses include prolonged estrogen exposure stimulating osteoblastic activity
    in the frontal bone inner table (supported by large-scale anthropological studies)
    and elevated leptin levels associated with obesity promoting bone formation. A
    more
    contested hypothesis involves dysregulated growth hormone secretion from pituitary
    microadenomatosis; however, recent evidence shows no direct causative role for
    GH
    excess or hyperprolactinemia in HFI etiopathogenesis. The condition predominantly
    affects females and is associated with age, being much less frequent in females
    under 40 years.
  cell_types:
  - preferred_term: Osteoblast
    term:
      id: CL:0000062
      label: osteoblast
  biological_processes:
  - preferred_term: Bone mineralization
    term:
      id: GO:0030282
      label: bone mineralization
  - preferred_term: Osteoblast differentiation
    term:
      id: GO:0001649
      label: osteoblast differentiation
  locations:
  - preferred_term: Frontal bone
    term:
      id: UBERON:0000209
      label: tetrapod frontal bone
  downstream:
  - target: Hyperostosis frontalis interna
  - target: Obesity
  - target: Increased intracranial pressure from frontal bone expansion
  evidence:
  - reference: PMID:10407462
    reference_title: "Hyperostosis frontalis interna: an anthropological perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is most commonly found among females and is believed to be associated with prolonged estrogen stimulation"
    explanation: Establishes the estrogen hypothesis for HFI pathogenesis based on a large-scale anthropological study of over 1,700 skulls.
  - reference: PMID:10407462
    reference_title: "Hyperostosis frontalis interna: an anthropological perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "While its magnitude of manifestation and frequency are much higher in females, HFI is not a purely female phenomenon. Males with hormonal disturbances such as atrophic testis were found to manifest HFI type D."
    explanation: The association of HFI with hormonal disturbances in males further supports the endocrine-mediated pathogenesis hypothesis.
  - reference: PMID:36217295
    reference_title: "Hyperostosis Frontalis Interna and a Question on Its Pathology: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is most often found in women after menopause. It is also associated with hormonal imbalance, being overweight, history of headaches, and neurocognitive degenerative conditions. Female gender, advanced age, extended estrogen stimulation, and elevated leptin levels may also play a role."
    explanation: Summarizes the leading etiological theories including estrogen, leptin, and hormonal imbalance for HFI development.
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "Although the frequency of HFI is 22% in patients with acromegaly, neither excess GH nor hyperprolactinemia plays a role in its etiopathogenesis. Various genetic or epigenetic factors may contribute to its etiology."
    explanation: While HFI is more frequent in acromegaly, this study found no direct role for GH excess or hyperprolactinemia, suggesting genetic/epigenetic factors instead.
  - reference: PMID:23284007
    reference_title: "Full penetrance of Morgagni-Stewart-Morel syndrome in a 75-year-old woman: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Endocrine or nutritional disorders may have led to an altered bone metabolism with frontal bone apposition."
    explanation: Supports the concept that endocrine and metabolic dysfunction drives altered bone metabolism leading to frontal hyperostosis.
- name: Neurological compression from calvarial thickening
  description: >
    Progressive thickening of the frontal bone inner table can lead to compression
    of underlying brain parenchyma, particularly the frontal lobes. This mechanical
    compression may result in cerebral atrophy, cognitive impairment,
    neuropsychiatric symptoms including depression and anxiety, headaches,
    seizures, and cranial nerve dysfunction affecting olfaction and vision.
  cell_types:
  - preferred_term: Neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: Neuron apoptotic process
    term:
      id: GO:0051402
      label: neuron apoptotic process
  locations:
  - preferred_term: Frontal cortex
    term:
      id: UBERON:0001870
      label: frontal cortex
  downstream:
  - target: Cognitive impairment
  - target: Depression
  - target: Seizures
  - target: Increased intracranial pressure from frontal bone expansion
  - target: Vertigo
  evidence:
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In she were performed imaging of the skull where was observed the presence of extensive hyperostosis frontalis interna, cortical atrophy and a left thalamic lacunar infarction."
    explanation: Imaging findings demonstrate the association between HFI and cortical atrophy in a patient with MSM syndrome.
  - reference: PMID:25382447
    reference_title: "Neuropsychological profile of a male psychiatric patient with a Morgagni-Stewart-Morel syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In 1928 Stewart and in 1930 Morel added neuropsychiatric symptoms, e.g. depression and dementia, which led to the definition of the Morgagni-Stewart-Morel Syndrome (MSM)."
    explanation: Establishes the historical association between HFI and neuropsychiatric symptoms including depression and dementia as core features of MSM.
  - reference: PMID:23284007
    reference_title: "Full penetrance of Morgagni-Stewart-Morel syndrome in a 75-year-old woman: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "the severity of our patient's neurological and psychiatric symptoms correlates well with the severity of her hyperostosis frontalis interna and the cortical atrophy."
    explanation: Demonstrates dose-response relationship between HFI severity and neuropsychiatric symptom severity, supporting mechanical compression.
- name: Hyperprolactinemia-associated endocrine dysfunction
  description: >
    Hyperostosis frontalis interna is strongly associated with acromegaly and
    hyperprolactinemia, particularly when both conditions coexist. Elevated
    prolactin levels may contribute to menstrual disturbances, galactorrhea,
    and hirsutism observed in MSM syndrome. The relationship between HFI
    and hyperprolactinemia appears to be particularly strong in acromegalic
    patients.
  cell_types:
  - preferred_term: Mammotroph
    term:
      id: CL:0002311
      label: mammotroph
  biological_processes:
  - preferred_term: Prolactin secretion
    term:
      id: GO:0070459
      label: prolactin secretion
  locations:
  - preferred_term: Anterior pituitary gland
    term:
      id: UBERON:0002196
      label: adenohypophysis
  downstream:
  - target: Amenorrhea
  - target: Galactorrhea
  - target: Hirsutism
  evidence:
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
    explanation: Demonstrates a highly significant association between hyperprolactinemia and HFI in acromegalic patients.
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The cause of HFI remains unknown but appears to be strongly associated with acromegaly, particularly in the presence of co-existent hyperprolactinaemia."
    explanation: Supports the association between HFI and hyperprolactinemia as a contributing pathway in MSM syndrome.
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "There was no difference between the HFI positive and negative acromegalic patients in basal GH, IGF-1, and PRL levels, IGF-1 index, diagnosis lag time, and insulin resistance."
    explanation: A more recent study found no difference in prolactin levels between HFI-positive and HFI-negative acromegalic patients, suggesting the relationship may be indirect.
- name: Increased intracranial pressure from frontal bone expansion
  description: >
    Progressive frontal bone thickening can result in increased intracranial pressure
    due to reduced intracranial volume and potential obstruction of CSF flow pathways.
    This increased pressure may contribute to headaches and other neurological symptoms
    observed in MSM syndrome. The mechanism links the skeletal abnormality (hyperostosis)
    to neurological manifestations through biomechanical effects.
  biological_processes:
  - preferred_term: Regulation of body fluid levels
    term:
      id: GO:0050878
      label: regulation of body fluid levels
  locations:
  - preferred_term: Cranial cavity
    term:
      id: UBERON:0013411
      label: cranial cavity
  downstream:
  - target: Headache
  evidence:
  - reference: PMID:36217295
    reference_title: "Hyperostosis Frontalis Interna and a Question on Its Pathology: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is most often found in women after menopause. It is also associated with hormonal imbalance, being overweight, history of headaches, and neurocognitive degenerative conditions."
    explanation: Establishes the association between HFI and headaches in affected individuals, supporting the increased ICP hypothesis.
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In she were performed imaging of the skull where was observed the presence of extensive hyperostosis frontalis interna, cortical atrophy and a left thalamic lacunar infarction."
    explanation: The imaging findings of cortical atrophy in conjunction with extensive HFI support the hypothesis of increased intracranial pressure effects.
phenotypes:
- name: Hyperostosis frontalis interna
  description: >
    Bilateral, irregular thickening of the inner table of the frontal bone,
    typically sparing the midline at the superior sagittal sinus. This is the
    defining radiological feature, usually discovered incidentally on skull
    X-ray, CT, or MRI.
  frequency: HP_0040281
  diagnostic: true
  category: Skeletal
  phenotype_term:
    preferred_term: Hyperostosis frontalis interna
    term:
      id: HP:0004438
      label: Hyperostosis frontalis interna
  evidence:
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hyperostosis frontalis interna was first described in 1719 in association with obesity and hirsutism, forming Morgagni's syndrome."
    explanation: Confirms hyperostosis frontalis interna as the defining feature of the syndrome, historically described from its first report.
  - reference: PMID:10407462
    reference_title: "Hyperostosis frontalis interna: an anthropological perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hyperostosis frontalis interna (HFI) is manifested by the accretion of bone on the inner table of the frontal bone."
    explanation: Defines HFI as bone accretion on the inner table of the frontal bone, consistent with the phenotype description.
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The anomaly exclusively involves the inner table and constantly spares the diploe and the external table."
    explanation: Specifies that HFI exclusively affects the inner table, sparing the diploe and external table.
- name: Obesity
  description: >
    Central obesity is a cardinal feature, present in the majority of affected
    individuals. It may be related to endocrine dysregulation including leptin
    resistance and growth hormone abnormalities.
  frequency: HP_0040282
  category: Metabolic
  phenotype_term:
    preferred_term: Obesity
    term:
      id: HP:0001513
      label: Obesity
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment."
    explanation: Obesity is documented as a core feature in this twin case report of MSM syndrome.
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "During this hospital stay the presence of grade I obesity, hyperglycemia, hypertriglyceridemia and hyperuricemia was documented."
    explanation: Obesity and metabolic disturbances documented in a clinical case of MSM syndrome.
  - reference: PMID:36452994
    reference_title: "Morgagni-Stewart-Morel syndrome presenting with neurological symptoms: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Morgagni-Stewart-Morel (MSM) syndrome is characterized by the thickening of the frontal bone of the skull (hyperostosis frontalis interna) obesity, neurological symptoms, and hypertrichosis."
    explanation: Obesity is listed as a defining feature of MSM syndrome.
- name: Headache
  description: >
    Chronic headaches are a common presenting symptom, potentially related to
    increased intracranial pressure from calvarial thickening or direct
    compression effects.
  frequency: HP_0040282
  category: Neurological
  phenotype_term:
    preferred_term: Headache
    term:
      id: HP:0002315
      label: Headache
  evidence:
  - reference: PMID:36452994
    reference_title: "Morgagni-Stewart-Morel syndrome presenting with neurological symptoms: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We present the case of a 76-year-old patient who complained of confusion, extreme irritability, and headache and was diagnosed with MSM based on examination, imaging, and test results."
    explanation: Headache is documented as a presenting symptom in this case of MSM syndrome.
  - reference: PMID:23284007
    reference_title: "Full penetrance of Morgagni-Stewart-Morel syndrome in a 75-year-old woman: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 75-year-old woman presented with severe frontal headache and a history of psychotic disorders."
    explanation: Severe frontal headache was the presenting symptom in this case of full-penetrance MSM syndrome.
- name: Seizures
  description: >
    Generalized seizures may occur, potentially related to frontal lobe
    compression from the hyperostotic bone. Seizures have been reported
    since early adulthood in some patients.
  frequency: HP_0040283
  category: Neurological
  phenotype_term:
    preferred_term: Seizure
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "They both have suffered from generalized seizures since their early adulthood."
    explanation: Both monozygotic twins with MSM syndrome had generalized seizures since early adulthood, supporting seizures as a feature of the syndrome.
- name: Cognitive impairment
  description: >
    Progressive cognitive decline may develop, attributed to frontal lobe
    compression and atrophy from the expanding inner table of the skull.
  frequency: HP_0040283
  category: Neurological
  phenotype_term:
    preferred_term: Cognitive impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We report two 71-year-old female monozygotic twins presenting with advanced hyperostosis frontalis interna, obesity, shortness and cognitive impairment."
    explanation: Cognitive impairment is documented in both twins with MSM syndrome.
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
    explanation: Cognitive impairment is part of the clinical presentation in this case of MSM syndrome.
- name: Depression
  description: >
    Depressive symptoms are frequently reported and may be related to frontal
    lobe dysfunction or the broader neuropsychiatric component of the syndrome.
  frequency: HP_0040283
  category: Psychiatric
  phenotype_term:
    preferred_term: Depression
    term:
      id: HP:0000716
      label: Depression
  evidence:
  - reference: PMID:25382447
    reference_title: "Neuropsychological profile of a male psychiatric patient with a Morgagni-Stewart-Morel syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In 1928 Stewart and in 1930 Morel added neuropsychiatric symptoms, e.g. depression and dementia, which led to the definition of the Morgagni-Stewart-Morel Syndrome (MSM)."
    explanation: Depression is one of the classic neuropsychiatric features that helped define MSM syndrome.
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Moreover, the patients showed some additional conditions only occurring in one individual or the other such as migraine, marked recurrent depressive disorder or polyarthrosis."
    explanation: Recurrent depressive disorder documented in one of the monozygotic twins with MSM syndrome.
- name: Hirsutism
  description: >
    Excess body hair growth in a male pattern distribution in affected females,
    related to the virilism component of the syndrome and potentially linked
    to hyperprolactinemia or androgen dysregulation.
  frequency: HP_0040283
  category: Dermatological
  phenotype_term:
    preferred_term: Hirsutism
    term:
      id: HP:0001007
      label: Hirsutism
  evidence:
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hyperostosis frontalis interna was first described in 1719 in association with obesity and hirsutism, forming Morgagni's syndrome."
    explanation: Hirsutism was one of the original features described by Morgagni in 1719 alongside HFI and obesity.
  - reference: PMID:36452994
    reference_title: "Morgagni-Stewart-Morel syndrome presenting with neurological symptoms: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Morgagni-Stewart-Morel (MSM) syndrome is characterized by the thickening of the frontal bone of the skull (hyperostosis frontalis interna) obesity, neurological symptoms, and hypertrichosis."
    explanation: Hypertrichosis (hirsutism) is listed as a defining feature of MSM syndrome.
- name: Vertigo
  description: >
    Dizziness and vertigo are reported neurological symptoms, potentially
    related to cranial nerve involvement or intracranial pressure changes.
  frequency: HP_0040283
  category: Neurological
  phenotype_term:
    preferred_term: Vertigo
    term:
      id: HP:0002321
      label: Vertigo
  evidence:
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
    explanation: Dizziness documented as part of the clinical presentation in a case of MSM syndrome.
- name: Amenorrhea
  description: >
    Menstrual disturbances including amenorrhea are part of the endocrine
    manifestations of the syndrome, potentially linked to hyperprolactinemia
    or hypothalamic-pituitary dysfunction.
  frequency: HP_0040283
  category: Endocrine
  phenotype_term:
    preferred_term: Amenorrhea
    term:
      id: HP:0000141
      label: Amenorrhea
  evidence:
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
    explanation: Hyperprolactinemia is strongly associated with HFI, and amenorrhea is a well-established consequence of hyperprolactinemia.
- name: Galactorrhea
  description: >
    Inappropriate lactation related to hyperprolactinemia, which has been
    found in a significant proportion of patients with hyperostosis frontalis
    interna.
  frequency: HP_0040284
  category: Endocrine
  phenotype_term:
    preferred_term: Galactorrhea
    term:
      id: HP:0100829
      label: Galactorrhea
  evidence:
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The cause of HFI remains unknown but appears to be strongly associated with acromegaly, particularly in the presence of co-existent hyperprolactinaemia."
    explanation: Hyperprolactinemia is strongly associated with HFI. Galactorrhea is a direct clinical manifestation of hyperprolactinemia.
- name: Diabetes mellitus
  description: >
    Type 2 diabetes mellitus and insulin resistance are frequent metabolic
    manifestations of the syndrome, likely related to the underlying endocrine
    dysregulation and obesity.
  frequency: HP_0040283
  category: Endocrine
  phenotype_term:
    preferred_term: Diabetes mellitus
    term:
      id: HP:0000819
      label: Diabetes mellitus
  evidence:
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 74 years old female with a history of exposure to wood smoke, vitiligo, type 2 diabetes mellitus, hypertension and cognitive impairment who enters the hospital by malaise, dizziness, anxiety, confusion, disorientation and difficulty walking."
    explanation: Type 2 diabetes mellitus is documented as a comorbidity in this MSM syndrome case report.
  - reference: PMID:27428347
    reference_title: "[Morgagni-Stewart-Morel syndrome. Case report and review of the literature]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "During this hospital stay the presence of grade I obesity, hyperglycemia, hypertriglyceridemia and hyperuricemia was documented."
    explanation: Hyperglycemia and metabolic disturbances are documented features of MSM syndrome.
  - reference: PMID:23284007
    reference_title: "Full penetrance of Morgagni-Stewart-Morel syndrome in a 75-year-old woman: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Metabolic and endocrine dysfunctions should be interpreted not only as isolated components of the syndrome, but also as the reason behind its pathogenesis."
    explanation: Metabolic dysfunctions including glucose dysregulation are considered integral components of MSM syndrome.
- name: Diabetes insipidus
  description: >
    Diabetes insipidus has been reported as an endocrine manifestation in some
    patients, potentially related to hypothalamic-pituitary dysfunction.
  frequency: HP_0040284
  category: Endocrine
  phenotype_term:
    preferred_term: Diabetes insipidus
    term:
      id: HP:0000873
      label: Diabetes insipidus
  notes: >
    Diabetes insipidus was reported in association with metabolic craniopathy
    (hyperostosis frontalis interna) by Dann (1951, Ann Intern Med 34:163-202,
    PMID:14790546), but this early report predates modern abstract indexing and
    no quotable abstract is available. A 1963 Russian-language review
    (PMID:14149113) also lists diabetes insipidus among hypothalamic-pituitary
    syndromes including HFI. The association remains poorly documented in the
    modern literature with no recent case series providing quantitative data.
biochemical:
- name: Growth hormone
  presence: Elevated
  context: Basal plasma growth hormone levels slightly increased with failure to suppress after glucose loading
  biomarker_term:
    preferred_term: Growth hormone
    term:
      id: NCIT:C2288
      label: Somatotropin
  evidence:
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "The frequency of HFI was higher in acromegalic patients than in the controls (22%, 0%, and 2.2%, respectively)."
    explanation: HFI is significantly more frequent in patients with GH excess (acromegaly), though the study found no direct causal role for GH in HFI etiopathogenesis.
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "There was a higher prevalence of HFI in the skull X-rays of the acromegalic cohort (P = 0.0002) when compared to the control group."
    explanation: Highly significant association between acromegaly (GH excess) and HFI prevalence.
- name: Prolactin
  presence: Elevated
  context: Hyperprolactinemia found in patients with hyperostosis frontalis interna and galactorrhea
  biomarker_term:
    preferred_term: Prolactin
    term:
      id: NCIT:C778
      label: Prolactin
  evidence:
  - reference: PMID:2349162
    reference_title: "Hyperostosis frontalis interna, acromegaly and hyperprolactinaemia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Acromegalic patients with hyperprolactinaemia also expressed HFI in a higher proportion of individuals than the control group (P = 0.0001)."
    explanation: Highly significant association between hyperprolactinemia and HFI in acromegalic patients.
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: "There was no difference between the HFI positive and negative acromegalic patients in basal GH, IGF-1, and PRL levels, IGF-1 index, diagnosis lag time, and insulin resistance."
    explanation: While hyperprolactinemia has been historically associated with MSM, this study found no difference in prolactin levels between HFI-positive and HFI-negative acromegalic patients.
genetic:
- name: Familial hyperostosis frontalis interna
  association: Susceptibility
  notes: >
    Familial aggregation documented across multiple generations with predominantly
    female involvement. Monozygotic twin concordance supports a genetic basis.
    The specific genes involved have not been identified. Inheritance pattern
    is consistent with autosomal dominant with sex-influenced expression, though
    X-linked dominant inheritance cannot be excluded.
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
    explanation: Identical phenotype in monozygotic twins provides strong evidence for a genetic basis of MSM syndrome.
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Various genetic or epigenetic factors may contribute to its etiology."
    explanation: Supports the hypothesis that genetic or epigenetic factors underlie HFI susceptibility.
environmental:
- name: Prolonged estrogen exposure
  description: >
    Extended exposure to endogenous estrogen, as seen in postmenopausal women
    with a history of obesity, is hypothesized to contribute to the development
    of hyperostosis frontalis interna through stimulation of osteoblastic
    activity in the frontal bone.
  exposure_term:
    preferred_term: exposure to estrogens
    term:
      id: ECTO:9000010
      label: exposure to estrogens
  evidence:
  - reference: PMID:10407462
    reference_title: "Hyperostosis frontalis interna: an anthropological perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "It is most commonly found among females and is believed to be associated with prolonged estrogen stimulation"
    explanation: Large-scale anthropological study supports prolonged estrogen stimulation as a contributing factor to HFI development.
  - reference: PMID:10407462
    reference_title: "Hyperostosis frontalis interna: an anthropological perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "HFI is associated with age insofar as it is much less frequent in females under 40 years of age."
    explanation: Age-related increase in HFI frequency is consistent with cumulative estrogen exposure as a risk factor.
  - reference: PMID:36217295
    reference_title: "Hyperostosis Frontalis Interna and a Question on Its Pathology: A Case Report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Female gender, advanced age, extended estrogen stimulation, and elevated leptin levels may also play a role."
    explanation: Identifies extended estrogen stimulation as a potential contributing factor for HFI development.
treatments:
- name: Symptomatic headache management
  description: >
    Standard analgesic medications for management of chronic headaches
    associated with the syndrome.
  treatment_term:
    preferred_term: Symptomatic headache management
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:23284007
    reference_title: "Full penetrance of Morgagni-Stewart-Morel syndrome in a 75-year-old woman: case report and review of the literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A 75-year-old woman presented with severe frontal headache and a history of psychotic disorders."
    explanation: Severe frontal headache is a prominent presenting symptom in MSM syndrome requiring pharmacological management.
  - reference: PMID:36452994
    reference_title: "Morgagni-Stewart-Morel syndrome presenting with neurological symptoms: a case report."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We present the case of a 76-year-old patient who complained of confusion, extreme irritability, and headache and was diagnosed with MSM based on examination, imaging, and test results."
    explanation: Headache is documented as a presenting complaint requiring symptomatic treatment in MSM.
- name: Antiepileptic therapy
  description: >
    Standard antiepileptic medications for management of seizures when present.
  treatment_term:
    preferred_term: Antiepileptic therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "They both have suffered from generalized seizures since their early adulthood."
    explanation: Generalized seizures from early adulthood in MSM patients require ongoing antiepileptic management.
- name: Multidisciplinary management
  description: >
    Comprehensive care targeting the neurological, endocrine, and metabolic
    components of the syndrome through coordinated multidisciplinary care.
  treatment_term:
    preferred_term: Multidisciplinary management
    term:
      id: MAXO:0000950
      label: supportive care
  evidence:
  - reference: PMID:41229651
    reference_title: "Morgagni-Stewart-Morel Syndrome Presenting as Acute Neurological and Respiratory Distress."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "A multidisciplinary approach targeting the neurological, endocrine, and respiratory components led to progressive clinical improvement and a favourable recovery."
    explanation: Multidisciplinary management targeting multiple organ systems led to favorable outcomes in an acute MSM case.
  - reference: PMID:41229651
    reference_title: "Morgagni-Stewart-Morel Syndrome Presenting as Acute Neurological and Respiratory Distress."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Multidisciplinary collaboration is crucial in managing complex cases of Morgagni-Stewart-Morel syndrome, especially in acute settings where diagnosis is challenging."
    explanation: Authors emphasize the importance of multidisciplinary collaboration for MSM syndrome management.
- name: Genetic counseling
  description: >
    Recommended for patients and their families given the evidence for
    genetic predisposition in the syndrome.
  treatment_term:
    preferred_term: Genetic counseling
    term:
      id: MAXO:0000079
      label: genetic counseling
  evidence:
  - reference: PMID:16909048
    reference_title: "Evidence of a genetic basis of Morgagni-Stewart-Morel syndrome. A case report of identical twins."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The symptoms common to both twins appear to correspond to the Morgagni-Stewart-Morel syndrome and indicate a genetic basis of this disorder as these features occur in genetically identical patients."
    explanation: Evidence for a genetic basis supports the recommendation for genetic counseling in affected families.
prevalence:
- population: General population (hyperostosis frontalis interna)
  percentage: 2.5
  notes: >
    Hyperostosis frontalis interna is found in approximately 2.5% of the general
    population, though full Morgagni-Stewart-Morel syndrome with the complete
    triad is much rarer. The condition is approximately 9 times more common
    in females than males and increases in frequency with age.
  evidence:
  - reference: PMID:36223065
    reference_title: "Frequency of hyperostosis frontalis interna in patients with active acromegaly: is there a possible role of GH excess or hyperprolactinemia in its etiopathogenesis?"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The frequency of HFI was higher in acromegalic patients than in the controls (22%, 0%, and 2.2%, respectively)."
    explanation: The 2.2% frequency in healthy controls is consistent with the reported general population prevalence of approximately 2.5%.
  - reference: PMID:15228235
    reference_title: "Hyperostosis frontalis interna: case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hyperostosis frontalis interna (HFI) has been reported in high frequency among post-menopausal elderly women."
    explanation: Supports the observation that HFI is relatively common particularly among postmenopausal women.
differential_diagnoses:
- name: Paget disease of bone
  disease_term:
    preferred_term: bone Paget disease
    term:
      id: MONDO:0005382
      label: bone Paget disease
  distinguishing_features:
  - Paget disease involves both inner and outer tables and diploe with characteristic cotton-wool appearance on imaging, unlike HFI which exclusively affects the inner table.
  evidence:
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
    explanation: Paget disease is listed as a major differential diagnosis for cranial hyperostosis.
  - reference: PMID:15228235
    reference_title: "Hyperostosis frontalis interna: case report and review of literature."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "HFI should be recognized as a benign entity and distinguished from other disorders that involve the frontal skull bone, such as Paget's disease, acromegaly, and malignancy."
    explanation: Emphasizes the importance of distinguishing HFI from Paget disease and other conditions affecting the frontal skull bone.
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The anomaly exclusively involves the inner table and constantly spares the diploe and the external table."
    explanation: The key distinguishing feature is that HFI exclusively affects the inner table, while Paget disease involves all layers.
- name: Meningioma
  disease_term:
    preferred_term: meningioma
    term:
      id: MONDO:0016642
      label: meningioma
  distinguishing_features:
  - Meningiomas can cause focal hyperostosis but typically present as a mass lesion with contrast enhancement on imaging, unlike the diffuse bilateral inner table thickening of HFI.
  evidence:
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
    explanation: Meningioma is listed as a major differential diagnosis for cranial hyperostosis.
- name: Fibrous dysplasia
  disease_term:
    preferred_term: fibrous dysplasia
    term:
      id: MONDO:0000845
      label: fibrous dysplasia
  distinguishing_features:
  - Fibrous dysplasia involves replacement of normal bone with fibrous tissue and has a ground-glass appearance on imaging, affecting the diploe rather than the inner table exclusively.
  evidence:
  - reference: PMID:36484746
    reference_title: "[Hyperostosis frontalis interna : etiology and differential diagnosis]."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The main differential diagnosis of cranial hyperostosis is made between meningioma, osteoma, Paget's disease and fibrous dysplasia."
    explanation: Fibrous dysplasia is listed as a major differential diagnosis for cranial hyperostosis.
classifications:
  harrisons_chapter:
  - classification_value: IMMUNE_RHEUMATOLOGIC
  - classification_value: NEUROLOGIC
  - classification_value: ENDOCRINOLOGY_METABOLISM
notes: >
  Morgagni-Stewart-Morel syndrome was first described by Giovanni Battista Morgagni
  in 1719 in an obese female with hirsutism found to have frontal hyperostosis at
  autopsy. Stewart reported three autopsy cases in 1928, and Morel described the
  first living case in 1930. The syndrome remains poorly understood, with debate
  about whether it represents a distinct entity or a syndrome complex. Diagnosis
  is based on the radiological finding of hyperostosis frontalis interna combined
  with obesity and neuropsychiatric features. There is ongoing debate about the
  existence of the syndrome as a unified entity given the high prevalence of HFI
  in the general population. A high prevalence and a lack of studies demonstrating
  a strong correlation between the different signs currently question the existence
  of the syndrome as a discrete entity.
references:
- reference: PMID:41229651
  title: Morgagni-Stewart-Morel Syndrome Presenting as Acute Neurological and Respiratory Distress.
  found_in:
  - Morgagni-Stewart-Morel_Syndrome-deep-research-falcon.md
  findings:
  - statement: Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise.
    supporting_text: Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise, not just chronic neuropsychiatric symptoms.
    evidence:
    - reference: PMID:41229651
      reference_title: Morgagni-Stewart-Morel Syndrome Presenting as Acute Neurological and Respiratory Distress.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise, not just chronic neuropsychiatric symptoms.
      explanation: Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
- reference: DOI:10.18663/tjcl.453912
  title: 'Morgagni-Steawart-Morel syndrome: Case report'
  found_in:
  - Morgagni-Stewart-Morel_Syndrome-deep-research-falcon.md
  findings:
  - statement: Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone.
    supporting_text: Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone.
    evidence:
    - reference: DOI:10.18663/tjcl.453912
      reference_title: 'Morgagni-Steawart-Morel syndrome: Case report'
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone.
      explanation: Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
- reference: DOI:10.2478/rjr-2024-0018
  title: The multidetector CT evaluation of diffuse hyperostosis frontalis interna
  found_in:
  - Morgagni-Stewart-Morel_Syndrome-deep-research-falcon.md
  findings:
  - statement: Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone.
    supporting_text: Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone.
    evidence:
    - reference: DOI:10.2478/rjr-2024-0018
      reference_title: The multidetector CT evaluation of diffuse hyperostosis frontalis interna
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone.
      explanation: Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
- reference: DOI:10.53446/actamednicomedia.1644183
  title: Hyperostosis Frontalis Interna and Its Clinical Significance
  found_in:
  - Morgagni-Stewart-Morel_Syndrome-deep-research-falcon.md
  findings:
  - statement: The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important.
    supporting_text: The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important.
    evidence:
    - reference: DOI:10.53446/actamednicomedia.1644183
      reference_title: Hyperostosis Frontalis Interna and Its Clinical Significance
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important.
      explanation: Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
- reference: DOI:10.7759/cureus.41445
  title: 'Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report'
  found_in:
  - Morgagni-Stewart-Morel_Syndrome-deep-research-falcon.md
  findings:
  - statement: 'Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report'
    supporting_text: 'Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report'
📚

References & Deep Research

References

5
PMID:41229651
Morgagni-Stewart-Morel Syndrome Presenting as Acute Neurological and Respiratory Distress.
1 finding
Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise.
"Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise, not just chronic neuropsychiatric symptoms."
Show evidence (1 reference)
PMID:41229651 SUPPORT Human Clinical
"Morgagni-Stewart-Morel syndrome can exceptionally present with acute neurological and respiratory compromise, not just chronic neuropsychiatric symptoms."
Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
DOI:10.18663/tjcl.453912
Morgagni-Steawart-Morel syndrome: Case report
1 finding
Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone.
"Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone."
Show evidence (1 reference)
DOI:10.18663/tjcl.453912 SUPPORT Human Clinical
"Hyperostosis frontalis interna (HOFI) is characterized by the benign growth of the inner plate of the frontal bone."
Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
DOI:10.2478/rjr-2024-0018
The multidetector CT evaluation of diffuse hyperostosis frontalis interna
1 finding
Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone.
"Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone."
Show evidence (1 reference)
DOI:10.2478/rjr-2024-0018 SUPPORT Human Clinical
"Hyperostosis frontalis interna (HFI) is a condition that involves the non-cancerous growth of the inner part of the frontal bone."
Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
DOI:10.53446/actamednicomedia.1644183
Hyperostosis Frontalis Interna and Its Clinical Significance
1 finding
The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important.
"The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important."
Show evidence (1 reference)
DOI:10.53446/actamednicomedia.1644183 SUPPORT Human Clinical
"The metabolic, endocrinological, neurological, and psychological causes of heterotopic ossification in frontal bone have become increasingly important."
Deep research cited this publication as relevant literature for Morgagni-Stewart-Morel Syndrome.
DOI:10.7759/cureus.41445
Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report
1 finding
Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report
"Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report"

Deep Research

1
Falcon ▸
Disease Characteristics Research Template
Edison Scientific Literature 24 citations 2026-05-10T05:24:11.849232

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: Morgagni-Stewart-Morel Syndrome
  • MONDO ID: (if available)
  • Category: Complex

Research Objectives

Please provide a comprehensive research report on Morgagni-Stewart-Morel Syndrome covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
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  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
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  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
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  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
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12. Treatment

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For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
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  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
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  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

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    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
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  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
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  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Comprehensive Research Report: Morgagni–Stewart–Morel Syndrome (MSMS)

Executive summary (current understanding)

Morgagni–Stewart–Morel syndrome (MSMS; also “Morgagni syndrome” / “Stewart–Morel syndrome”) is typically used to describe the syndromic co-occurrence of hyperostosis frontalis interna (HFI) (benign thickening/proliferation of the inner table of the frontal bone) with metabolic/endocrine abnormalities (commonly obesity and diabetes; sometimes thyroid/parathyroid abnormalities) and neuropsychiatric/neurologic manifestations (headache, mood/cognitive/behavioral symptoms, seizures). The literature base remains dominated by case reports and small series, with uncertain causality between bone overgrowth and symptoms. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 7-8, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3)

Item Details Evidence (context id) Publication (year, journal) URL
Disease concept Morgagni–Stewart–Morel syndrome (MSMS/MSM) is a rare syndrome in which hyperostosis frontalis interna (HFI) co-occurs with metabolic, endocrine, and neuropsychiatric abnormalities; commonly described with obesity, virilization/hirsutism, headache, seizures, mood/cognitive symptoms, and endocrine dysfunction. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) 2025, Acta Medica Nicomedia; 2025, European Journal of Case Reports in Internal Medicine; 2019, Turkish Journal of Clinics and Laboratory https://doi.org/10.53446/actamednicomedia.1644183 ; https://doi.org/10.12890/2025_005836 ; https://doi.org/10.18663/tjcl.453912
Core skeletal lesion HFI is benign thickening/proliferation of the inner table of the frontal bone and is the principal radiologic feature of MSMS. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, inal2024themultidetectorct pages 7-8) 2025, European Journal of Case Reports in Internal Medicine; 2019, Turkish Journal of Clinics and Laboratory; 2024, Romanian Journal of Rhinology https://doi.org/10.12890/2025_005836 ; https://doi.org/10.18663/tjcl.453912 ; https://doi.org/10.2478/rjr-2024-0018
Common synonyms/alternate names Morgagni syndrome; Stewart–Morel syndrome; Morgagni–Stewart–Morel syndrome; metabolic craniopathy; hyperostosis frontalis interna with obesity/virilization/neuropsychiatric symptoms. Some sources loosely use HFI itself as synonymous, but retrieved evidence supports HFI as the imaging lesion and MSMS as the syndromic form. (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, inal2024themultidetectorct pages 7-8, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) 2019, Turkish Journal of Clinics and Laboratory; 2024, Romanian Journal of Rhinology https://doi.org/10.18663/tjcl.453912 ; https://doi.org/10.2478/rjr-2024-0018
Identifier: MONDO Not found in retrieved sources. (cetinok2025hyperostosisfrontalisinterna pages 5-6) 2025, Acta Medica Nicomedia https://doi.org/10.53446/actamednicomedia.1644183
Identifier: OMIM Not found in retrieved sources. (cetinok2025hyperostosisfrontalisinterna pages 5-6) 2025, Acta Medica Nicomedia https://doi.org/10.53446/actamednicomedia.1644183
Identifier: Orphanet Not found in retrieved sources. (cetinok2025hyperostosisfrontalisinterna pages 5-6) 2025, Acta Medica Nicomedia https://doi.org/10.53446/actamednicomedia.1644183
Identifier: MeSH Not found in retrieved sources. (cetinok2025hyperostosisfrontalisinterna pages 5-6) 2025, Acta Medica Nicomedia https://doi.org/10.53446/actamednicomedia.1644183
Identifier: ICD-10 / ICD-11 Not found in retrieved sources. (cetinok2025hyperostosisfrontalisinterna pages 5-6) 2025, Acta Medica Nicomedia https://doi.org/10.53446/actamednicomedia.1644183
Typical demographics Strong female predominance, especially postmenopausal and older women. In one CT series of diffuse HFI, 148/154 (96.1%) cases were female; a cadaveric study found HFI in 31/74 donors, with 77.42% of HFI cases in women. (inal2024themultidetectorct pages 3-4, inal2024themultidetectorct pages 1-3, cetinok2025hyperostosisfrontalisinterna pages 2-3) 2024, Romanian Journal of Rhinology; 2025, Acta Medica Nicomedia https://doi.org/10.2478/rjr-2024-0018 ; https://doi.org/10.53446/actamednicomedia.1644183
Endocrine/metabolic associations Reported associations include obesity, diabetes mellitus, hypothyroidism, hyperparathyroidism, menstrual disturbances, galactorrhea, and hirsutism/virilization. Etiology remains uncertain but hormonal/metabolic factors are repeatedly emphasized. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 7-8, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) 2025, European Journal of Case Reports in Internal Medicine; 2024, Romanian Journal of Rhinology; 2023, Cureus; 2019, Turkish Journal of Clinics and Laboratory https://doi.org/10.12890/2025_005836 ; https://doi.org/10.2478/rjr-2024-0018 ; https://doi.org/10.7759/cureus.41445 ; https://doi.org/10.18663/tjcl.453912
Neuropsychiatric/neurologic features Headache, depression, cognitive/behavioral change, psychosis, seizures, dizziness, and executive dysfunction have been reported; presentations range from incidental imaging findings to acute neurologic/respiratory decompensation. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5, abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) 2025, Acta Medica Nicomedia; 2025, European Journal of Case Reports in Internal Medicine; 2023, Cureus; 2019, Turkish Journal of Clinics and Laboratory https://doi.org/10.53446/actamednicomedia.1644183 ; https://doi.org/10.12890/2025_005836 ; https://doi.org/10.7759/cureus.41445 ; https://doi.org/10.18663/tjcl.453912
Core diagnostic element: imaging Diagnosis depends on radiographic confirmation of frontal inner-table thickening. CT is emphasized as confirmatory; MRI may show internal frontal hyperostosis and associated cortico-subcortical atrophy. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 7-8) 2025, European Journal of Case Reports in Internal Medicine; 2024, Romanian Journal of Rhinology https://doi.org/10.12890/2025_005836 ; https://doi.org/10.2478/rjr-2024-0018
Core diagnostic element: CT morphometry In diffuse HFI, CT shows increased frontal/calvarial thickness at the vertex, frontal tuberosity, and frontal sinus levels. Example vertex thicknesses in HFI vs controls: midline 12.88±3.43 mm vs 8.01±2.04 mm; right lateral 15.94±4.75 mm vs 8.69±1.96 mm; left lateral 15.48±4.66 mm vs 8.64±1.97 mm. (inal2024themultidetectorct pages 3-4, inal2024themultidetectorct pages 1-3) 2024, Romanian Journal of Rhinology https://doi.org/10.2478/rjr-2024-0018
Core diagnostic element: density findings CT density in HFI regions is increased at least at the vertex and frontal tuberosity. Example: vertex HFI region 1064.56±244.33 HU vs control 837.06±214.25 HU. (inal2024themultidetectorct pages 3-4, inal2024themultidetectorct pages 5-7, inal2024themultidetectorct pages 4-5) 2024, Romanian Journal of Rhinology https://doi.org/10.2478/rjr-2024-0018
Radiologic classification Retrieved sources reference Hershkovitz radiologic classification for HFI and describe Type A (<25% frontal endocranial surface, isolated thickness <1 cm) and Types B–D with increasing extent/nodularity; radiology reports should specify presence and degree. (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3, inal2024themultidetectorct media cb19ca47) 2019, Turkish Journal of Clinics and Laboratory; 2024, Romanian Journal of Rhinology https://doi.org/10.18663/tjcl.453912 ; https://doi.org/10.2478/rjr-2024-0018
Suggested diagnostic workflow Combine characteristic imaging (HFI) with syndromic features and assess endocrine/metabolic comorbidities. Retrieved studies recommend radiology consultation and endocrinologic assessment when HFI is detected. (inal2024themultidetectorct pages 7-8, inal2024themultidetectorct pages 1-3) 2024, Romanian Journal of Rhinology https://doi.org/10.2478/rjr-2024-0018
Differential diagnosis clues Retrieved reports note need to distinguish HFI/MSMS from Paget disease, fibrous dysplasia, acromegaly, hyperostosis cranialis interna, and osseous metastasis mimics on imaging. (inal2024themultidetectorct pages 7-8, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5) 2024, Romanian Journal of Rhinology; 2023, Cureus https://doi.org/10.2478/rjr-2024-0018 ; https://doi.org/10.7759/cureus.41445
Information source level The retrieved evidence is mainly aggregated disease-level interpretation built from case reports, case series, and imaging studies rather than large registries or EHR-derived population datasets. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, hiremath2024diagnosticchallengesand pages 1-3, dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, inal2024themultidetectorct pages 1-3) 2025, European Journal of Case Reports in Internal Medicine; 2024, case report; 2019, Turkish Journal of Clinics and Laboratory; 2024, Romanian Journal of Rhinology https://doi.org/10.12890/2025_005836 ; https://doi.org/10.18663/tjcl.453912 ; https://doi.org/10.2478/rjr-2024-0018

Table: This table summarizes how the retrieved literature defines Morgagni–Stewart–Morel syndrome and related hyperostosis frontalis interna, including synonyms, missing identifiers in the retrieved sources, and the main diagnostic features. It is useful as a quick normalization and diagnostic reference for knowledge-base curation.

1. Disease information

1.1 Concise overview

  • Disease definition (syndromic form): MSMS is the term applied when HFI coexists with metabolic, endocrine and neuropsychiatric abnormalities. One recent source explicitly frames the definition as: MSMS is used when HFI “coexists with metabolic, endocrine and neuropsychiatric abnormalities,” and when HFI occurs with “virilisation, obesity and neuropsychiatric issues” it is classified as MSMS. (cetinok2025hyperostosisfrontalisinterna pages 5-6)
  • Key lesion: HFI is repeatedly emphasized as the principal radiologic hallmark and the “only way to confirm” HFI is radiographic visualization of frontal inner-table thickening. (inal2024themultidetectorct pages 7-8, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2)

1.2 Key identifiers (ontology/clinical coding)

The retrieved primary sources did not provide MONDO, OMIM, Orphanet, MeSH, or ICD-10/ICD-11 mappings for MSMS/HFI; therefore, these identifiers cannot be confirmed from the tool-retrieved literature in this run. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

1.3 Synonyms and alternative names

  • Morgagni syndrome; Stewart–Morel syndrome; Morgagni–Stewart–Morel syndrome; “metabolic craniopathy” (term used in older clinical literature). (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3)
  • Some case literature uses HFI as “aka MSMS,” but other sources distinguish HFI (lesion) from MSMS (syndromic form). (hiremath2024diagnosticchallengesand pages 1-3, cetinok2025hyperostosisfrontalisinterna pages 5-6)

1.4 Evidence source type

Across retrieved sources, MSMS characterization is primarily derived from individual case reports, plus some aggregated imaging cohorts focused on HFI rather than MSMS specifically. (hiremath2024diagnosticchallengesand pages 1-3, inal2024themultidetectorct pages 1-3)

2. Etiology

2.1 Disease causal factors (current evidence)

No single validated causal gene or pathogen emerges from the retrieved literature; the etiology is consistently described as uncertain, with hormonal/metabolic drivers repeatedly hypothesized.

Hormonal/endocrine hypotheses - Long-term estrogen exposure and female sex/postmenopausal status are repeatedly discussed as central correlates of HFI/MSMS; one recent review-like paper states HFI occurs “nine times more frequently in women,” especially “postmenopausal women,” and links the condition to “long-term estrogen exposure,” obesity, diabetes, and endocrine imbalance. (cetinok2025hyperostosisfrontalisinterna pages 5-6) - Case-based MSMS descriptions emphasize association with endocrine abnormalities (notably hypothyroidism in an acute presentation report). (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4)

Metabolic hypotheses - Diabetes mellitus and obesity are commonly mentioned as associated conditions in MSMS/HFI. (inal2024themultidetectorct pages 7-8, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3)

Possible genetic contribution (low-evidence/older literature) - A case-report source notes possible autosomal dominant transmission as a hypothesis, but also states that overall etiology remains unexplained. (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3)

2.2 Risk factors

Supported/recurring risk associations in retrieved literature: - Female sex and postmenopausal age (strong association). (cetinok2025hyperostosisfrontalisinterna pages 5-6, inal2024themultidetectorct pages 1-3) - Obesity and diabetes mellitus. (cetinok2025hyperostosisfrontalisinterna pages 5-6, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5) - Endocrine disorders (e.g., hypothyroidism; hyperparathyroidism). (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 7-8, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3)

2.3 Protective factors

No protective genetic or environmental factors were identified in the retrieved sources.

2.4 Gene–environment interaction

No explicit gene–environment interaction studies were retrieved.

3. Phenotypes (clinical spectrum)

3.1 Core phenotypes (with suggested HPO terms)

The syndrome is variably expressed, ranging from incidental HFI to symptomatic neuropsychiatric and endocrine/metabolic disease.

A. Skeletal/imaging - Internal frontal hyperostosis / frontal inner-table thickening (core finding). (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 7-8) - Suggested HPO: Hyperostosis frontalis interna (HP term likely exists; if not, map to Hyperostosis [HP:0100775])

B. Neurologic & neuropsychiatric - Headache (often cited; hypothesized relation to thickening). (inal2024themultidetectorct pages 1-3, inal2024themultidetectorct pages 7-8) - HPO: Headache HP:0002315 - Seizures/epilepsy reported in some cases. (cetinok2025hyperostosisfrontalisinterna pages 5-6, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) - HPO: Seizures HP:0001250 - Depression and other psychiatric disturbances; cognitive/behavioral changes reported. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) - HPO: Depressed mood HP:0000716; Cognitive impairment HP:0100543; Abnormal behavior HP:0000708

C. Endocrine/metabolic - Obesity (common association). (cetinok2025hyperostosisfrontalisinterna pages 5-6, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) - HPO: Obesity HP:0001513 - Diabetes mellitus and other metabolic disorders mentioned. (dogan2019morgagnisteawartmorelsendromuolgu pages 3-3, inal2024themultidetectorct pages 7-8) - HPO: Diabetes mellitus HP:0000819 - Hypothyroidism emphasized in at least one acute MSMS case. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4) - HPO: Hypothyroidism HP:0000821 - Hyperparathyroidism mentioned as associated. (inal2024themultidetectorct pages 7-8, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) - HPO: Hyperparathyroidism HP:0000873

D. Androgen-related/virilization phenotype - Hirsutism/virilization is repeatedly described in the classic MSMS triad. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, dogan2019morgagnisteawartmorelsendromuolgu pages 3-3) - HPO: Hirsutism HP:0001007; Virilization HP:0000841

3.2 Onset, progression, severity (as reported)

  • Demographic and temporal statements in one source suggest mild HFI can appear in early adulthood, while advanced forms and/or psychological symptoms are usually later (e.g., after mid-30s). (cetinok2025hyperostosisfrontalisinterna pages 5-6)
  • Many patients are described as asymptomatic or having nonspecific symptoms. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

3.3 Frequency among affected individuals

Robust phenotype frequencies for MSMS were not identified in retrieved sources; most evidence is descriptive. However, sex distribution for diffuse HFI in a CT series is quantified (see Epidemiology/Statistics). (inal2024themultidetectorct pages 3-4, inal2024themultidetectorct pages 1-3)

3.4 Quality of life impact

Quality-of-life instruments (EQ-5D/SF-36/PROMIS) were not reported in retrieved sources. Clinical narratives suggest significant functional impact in some cases (e.g., cognitive/behavioral change, gait decline, urinary incontinence, seizures), but no standardized QoL quantification was retrievable. (hiremath2024diagnosticchallengesand pages 1-3)

4. Genetic / molecular information

4.1 Causal genes and pathogenic variants

  • No validated causal genes or pathogenic variants for MSMS were identified in retrieved sources.

4.2 Proposed molecular contributors (hypothesis-level)

  • One source discusses developmental bone formation mechanisms involving FGFR1 in neural crest cells (“The absence of Fgfr1 in neural crest cells results in heterotopic chondrogenesis and osteogenesis”), offered as mechanistic context for cranial heterotopic ossification rather than a proven MSMS mechanism. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

4.3 Suggested ontology mappings (hypothesis-level)

  • GO biological process candidates: osteoblast differentiation; bone mineralization; intramembranous ossification; bone remodeling.
  • CL cell types: osteoblast (CL:0000062), osteoclast (CL:0000092), osteocyte (CL:0000132).

5. Environmental information

No toxin, occupational, radiation, or infectious triggers were identified in the retrieved sources. The dominant non-genetic associations were metabolic/endocrine (obesity, diabetes, hypothyroidism), which may reflect lifestyle and aging but are not explicitly treated as environmental exposures in the retrieved literature. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2)

6. Mechanism / pathophysiology (proposed causal chains)

6.1 Leading mechanistic model (evidence-limited)

A recurring conceptual chain is: 1) Hormonal/metabolic dysregulation (e.g., estrogen exposure/imbalance; obesity/diabetes; hypothyroidism) (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2) → 2) Altered cranial bone remodeling with overgrowth of frontal inner table (HFI) (inal2024themultidetectorct pages 7-8, inal2024themultidetectorct pages 3-4) → 3) Potential mass effect / intracranial volume reduction / cortical interaction contributing to headaches, seizures, or neuropsychiatric symptoms in some patients; however the relationship is not conclusively established. (cetinok2025hyperostosisfrontalisinterna pages 5-6, abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4)

6.2 Imaging/functional correlates supporting mechanism hypotheses

  • A recent review-like paper states calvarial thickening may reduce intracranial volume, and discusses scintigraphy/PET findings with symmetric frontal uptake patterns (e.g., a “butterfly pattern” on bone scintigraphy), reflecting altered bone metabolism/activity. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

6.3 Suggested ontology mappings

  • UBERON (anatomy): frontal bone (UBERON:0001421); skull (UBERON:0003129); cerebral cortex (UBERON:0000956).
  • GO cellular component: extracellular matrix; bone extracellular matrix.

7. Anatomical structures affected

  • Primary: frontal bone inner table (HFI). (inal2024themultidetectorct pages 7-8)
  • Secondary/adjacent: potential compression/interaction with frontal lobes/dura; one case report notes frontal lobe compression with clinical syndrome and improvement after surgical intervention. (hiremath2024diagnosticchallengesand pages 1-3)

8. Temporal development

  • Typically described as a disorder of older women, often postmenopausal, with long-term progression of thickening. (cetinok2025hyperostosisfrontalisinterna pages 5-6, inal2024themultidetectorct pages 1-3)
  • Acute life-threatening presentations are reported but appear rare; one 2025 acute case highlights emergency recognition when HFI coexists with severe endocrine dysfunction. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2)

9. Inheritance and population

9.1 Epidemiology (statistics available from recent studies)

MSMS-specific population prevalence is not established in retrieved sources; HFI prevalence and sex distribution are better studied.

CT cohort (2024) – diffuse HFI - Retrospective CT cohort: 154 adults with diffuse HFI and 151 controls. Mean age of HFI group 69.33 ± 14.34 years. Sex distribution in HFI group: 148/154 (96.1%) female and 6/154 (3.9%) male. (In controls: 143/151 female, 8/151 male; p=0.559). (inal2024themultidetectorct pages 1-3, inal2024themultidetectorct pages 3-4)

Cadaveric cohort (2016–2019 sampling, published 2025) – HFI prevalence - 74 donors examined; HFI in 31/74 (41.89%). Reported sex-specific proportions: 32.43% in women and 9.45% in men (as presented by the authors for their sample). (cetinok2025hyperostosisfrontalisinterna pages 2-3)

9.2 Demographics

  • Strong female predominance, particularly postmenopausal age. (cetinok2025hyperostosisfrontalisinterna pages 5-6, inal2024themultidetectorct pages 1-3)

9.3 Inheritance

  • A possible autosomal dominant hypothesis is mentioned in older case-report literature, but no genetic validation was identified in retrieved sources. (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3)

10. Diagnostics

10.1 Clinical evaluation

  • MSMS diagnosis in practice appears to rely on recognizing HFI on imaging plus a compatible syndromic context (obesity/endocrinopathy/neuropsychiatric symptoms), with emphasis on multidisciplinary evaluation (neurology + endocrinology + radiology). (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2, inal2024themultidetectorct pages 1-3)

10.2 Imaging

  • CT: highlighted as confirmatory; the 2024 CT study quantified increased thickness at vertex, frontal tuberosity, and frontal sinus levels in diffuse HFI. Example vertex thickness (HFI vs controls): midline 12.88±3.43 mm vs 8.01±2.04 mm, right lateral 15.94±4.75 mm vs 8.69±1.96 mm, left lateral 15.48±4.66 mm vs 8.64±1.97 mm. (inal2024themultidetectorct pages 3-4)
  • CT density: example vertex density in HFI regions 1064.56±244.33 HU vs controls 837.06±214.25 HU. (inal2024themultidetectorct pages 3-4)
  • Imaging measurement approach (visual evidence): the CT measurement scheme for thickness/density at specified levels is shown in figures from the 2024 CT paper. (inal2024themultidetectorct media cb19ca47, inal2024themultidetectorct media a3b14aa3)

10.3 Differential diagnosis (radiology)

  • Suggested differentials in retrieved sources include Paget disease, fibrous dysplasia, acromegaly, other cranial hyperostosis syndromes, and other causes of calvarial thickening. (inal2024themultidetectorct pages 7-8, otken2023hyperostosisfrontoparietooccipitalisa pages 4-5)

10.4 Diagnostic criteria

No standardized diagnostic criteria or society guidelines were identified in the retrieved sources.

10.5 Genetic testing

No gene-based diagnostic strategy was supported by retrieved evidence.

11. Outcome / prognosis

  • Many cases are described as incidental/asymptomatic, suggesting benign course for HFI itself; nevertheless, symptomatic neuropsychiatric and endocrine complications can be clinically significant. (cetinok2025hyperostosisfrontalisinterna pages 5-6)
  • An acute case report demonstrates that severe endocrine dysfunction (profound hypothyroidism) with HFI can lead to respiratory failure and depressed consciousness, but clinical improvement followed supportive care and thyroid hormone replacement. (abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4)

No survival curves, mortality rates, or validated prognostic biomarkers were identified in the retrieved sources.

12. Treatment (current practice / real-world implementations)

No disease-modifying therapy for HFI/MSMS is established in retrieved sources; management is generally symptomatic and comorbidity-focused.

12.1 Multidisciplinary supportive care

  • One MSMS acute case emphasizes airway/ventilation stabilization and multisystem management; endocrine treatment (thyroid hormone replacement) was central to recovery when hypothyroidism was severe. (abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4)

12.2 Endocrine/metabolic management

  • The 2024 CT cohort recommends that when HFI is detected, endocrinological assessment should be performed and clinicians should consult radiology; it highlights the need to explore the HFI–headache relationship. (inal2024themultidetectorct pages 1-3, inal2024themultidetectorct pages 7-8)

12.3 Neurosurgical intervention (selected cases)

  • A 2024 case report describes frontal bone thickening with frontal lobe compression; it states that surgical intervention led to significant clinical improvement in that patient context. (hiremath2024diagnosticchallengesand pages 1-3)

12.4 MAXO suggestions (for knowledge base annotation)

  • Endocrine hormone replacement therapy (e.g., thyroid hormone replacement)
  • Metabolic disease management
  • Neurosurgical decompression / cranioplasty (selected cases)
  • Antiseizure medication (if seizures)

(These MAXO mappings are suggestions; specific MAXO IDs were not provided in retrieved sources.)

12.5 Clinical trials

A clinical trial search did not yield a clearly relevant interventional trial for MSMS/HFI within the retrieved trial record set. (clinical trials tool run produced no relevant trials)

13. Prevention

No MSMS-specific primary/secondary prevention strategies were identified in retrieved sources. Reasonable prevention concepts are indirect (management of obesity/diabetes/endocrine disorders), but direct evidence for prevention of HFI/MSMS is not established in retrieved literature. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

14. Other species / natural disease

No naturally occurring MSMS/HFI animal disease reports were identified in the retrieved sources.

15. Model organisms

No MSMS-specific model organism systems were identified in retrieved sources. Mechanistic discussion referencing FGFR1/neural crest perturbation was presented as developmental biology context rather than a validated MSMS model. (cetinok2025hyperostosisfrontalisinterna pages 5-6)

Recent developments (prioritizing 2023–2024)

2024: Quantitative CT characterization of diffuse HFI

  • A 2024 multidetector CT study (n=154 diffuse HFI) provided quantitative thickness/density data and reinforced the strong female predominance (96.1% female). It also recommended clinician recognition and endocrinologic assessment when HFI is detected. (inal2024themultidetectorct pages 1-3, inal2024themultidetectorct pages 3-4, inal2024themultidetectorct pages 7-8)

2024: Diagnostic pitfalls and management implications in neurology

  • A 2024 case report highlighted misdiagnosis risk (initially considered autoimmune encephalitis) and emphasized that HFI may present with neurobehavioral syndromes and that selected cases with compression may benefit from neurosurgical management. (hiremath2024diagnosticchallengesand pages 1-3)

2023: Continued reliance on case-based synthesis for MSMS

  • A 2023 anatomical case report reiterated the classic syndromic association: MSMS as HFI plus “hormonal imbalances, neuropsychiatric disease, and metabolic disturbances such as obesity and diabetes,” and emphasized that radiography is often required for detection. (otken2023hyperostosisfrontoparietooccipitalisa pages 4-5)

Expert opinions / authoritative analysis (from retrieved sources; evidence-limited)

Because MSMS is rare, “authoritative” views in the retrieved set largely come from radiology/anatomy reviews and case-report discussions: - A recent review-like article notes many patients are “typically asymptomatic or exhibit non-specific symptoms, including headache, neurological, or mental issues,” underscoring uncertainty about symptom attribution to HFI. (cetinok2025hyperostosisfrontalisinterna pages 5-6) - The 2024 CT cohort’s concluding clinical guidance is pragmatic (recognize imaging pattern, consider headache association, consult radiology, and evaluate endocrine status). (inal2024themultidetectorct pages 1-3)

Direct quotes from abstracts (from retrieved sources)

  • “Morgagni–Stewart–Morel (MSM) syndrome is the term used when hyperostosis frontalis interna (HFI) coexists with metabolic, endocrine and neuropsychiatric abnormalities.” (cetinok2025hyperostosisfrontalisinterna pages 5-6)
  • “The only way to confirm a diagnosis of HFI is through a radiographic image that clearly shows thickened bone.” (inal2024themultidetectorct pages 7-8)

Key limitations of this evidence package

  1. Ontology identifiers (MONDO/OMIM/Orphanet/MeSH/ICD) were not present in the retrieved sources and could not be verified here.
  2. PMIDs were not available in the retrieved excerpts/metadata for the key recent sources used.
  3. MSMS-specific epidemiology is poorly defined; most quantification is for HFI, not the full MSMS syndrome.
  4. Mechanistic claims are largely hypothesis-driven, with limited direct molecular evidence.

Primary URLs (publication dates where available)

  • Inal et al. “The multidetector CT evaluation of diffuse hyperostosis frontalis interna.” Jul 2024. https://doi.org/10.2478/rjr-2024-0018 (inal2024themultidetectorct pages 1-3)
  • Otken et al. “Hyperostosis Fronto-Parieto-Occipitalis: A Cadaveric Case Report.” Jul 2023. https://doi.org/10.7759/cureus.41445 (otken2023hyperostosisfrontoparietooccipitalisa pages 4-5)
  • Doğan & Mouline. “Morgagni-Steawart-Morel sendromu: Olgu sunumu.” Sep 2019. https://doi.org/10.18663/tjcl.453912 (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3)
  • Hiremath et al. “Diagnostic challenges and therapeutic implications of Hyperostosis Frontalis Interna (HFI)…” 2024 (journal/URL not available in retrieved record). (hiremath2024diagnosticchallengesand pages 1-3)
  • (Post-2024, included for completeness) Abdallah et al. MSMS acute presentation. Oct 2025. https://doi.org/10.12890/2025_005836 (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2)
  • (Post-2024, included for completeness) Çetinok. “Hyperostosis Frontalis Interna and Its Clinical Significance.” Jun 2025. https://doi.org/10.53446/actamednicomedia.1644183 (cetinok2025hyperostosisfrontalisinterna pages 5-6)

References

  1. (cetinok2025hyperostosisfrontalisinterna pages 5-6): Hürriyet Çetinok. Hyperostosis frontalis interna and its clinical significance. Acta Medica Nicomedia, 8:169-175, Jun 2025. URL: https://doi.org/10.53446/actamednicomedia.1644183, doi:10.53446/actamednicomedia.1644183. This article has 1 citations.

  2. (abdallah2025morgagnistewartmorelsyndromepresenting pages 1-2): Marwa Ben Abdallah, Aymen Farroukh, Faten Mzoughi, Houssem Affes, Mariam Mallek, Wassel Mokni, and Adel Chaari. Morgagni-stewart-morel syndrome presenting as acute neurological and respiratory distress. European Journal of Case Reports in Internal Medicine, Oct 2025. URL: https://doi.org/10.12890/2025_005836, doi:10.12890/2025_005836. This article has 0 citations.

  3. (inal2024themultidetectorct pages 7-8): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  4. (dogan2019morgagnisteawartmorelsendromuolgu pages 3-3): E. Doğan and M. Mouline. Morgagni-steawart-morel sendromu: olgu sunumu. Turkish Journal of Clinics and Laboratory, Sep 2019. URL: https://doi.org/10.18663/tjcl.453912, doi:10.18663/tjcl.453912. This article has 1 citations.

  5. (dogan2019morgagnisteawartmorelsendromuolgu pages 1-3): E. Doğan and M. Mouline. Morgagni-steawart-morel sendromu: olgu sunumu. Turkish Journal of Clinics and Laboratory, Sep 2019. URL: https://doi.org/10.18663/tjcl.453912, doi:10.18663/tjcl.453912. This article has 1 citations.

  6. (inal2024themultidetectorct pages 3-4): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  7. (inal2024themultidetectorct pages 1-3): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  8. (cetinok2025hyperostosisfrontalisinterna pages 2-3): Hürriyet Çetinok. Hyperostosis frontalis interna and its clinical significance. Acta Medica Nicomedia, 8:169-175, Jun 2025. URL: https://doi.org/10.53446/actamednicomedia.1644183, doi:10.53446/actamednicomedia.1644183. This article has 1 citations.

  9. (otken2023hyperostosisfrontoparietooccipitalisa pages 4-5): Emily Otken, Emily O'Brien, Braden Nyboer, Huy Nguyen, Cody Orvin, and Adegbenro O Fakoya. Hyperostosis fronto-parieto-occipitalis: a cadaveric case report. Cureus, Jul 2023. URL: https://doi.org/10.7759/cureus.41445, doi:10.7759/cureus.41445. This article has 1 citations.

  10. (abdallah2025morgagnistewartmorelsyndromepresenting pages 2-4): Marwa Ben Abdallah, Aymen Farroukh, Faten Mzoughi, Houssem Affes, Mariam Mallek, Wassel Mokni, and Adel Chaari. Morgagni-stewart-morel syndrome presenting as acute neurological and respiratory distress. European Journal of Case Reports in Internal Medicine, Oct 2025. URL: https://doi.org/10.12890/2025_005836, doi:10.12890/2025_005836. This article has 0 citations.

  11. (inal2024themultidetectorct pages 5-7): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  12. (inal2024themultidetectorct pages 4-5): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  13. (inal2024themultidetectorct media cb19ca47): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.

  14. (hiremath2024diagnosticchallengesand pages 1-3): PM Hiremath, A Mehta, and R Srinivasa. Diagnostic challenges and therapeutic implications of hyperostosis frontalis interna (hfi) in a post-menopausal woman-a case report. Unknown journal, 2024.

  15. (inal2024themultidetectorct media a3b14aa3): Mikail Inal, Nuray Bayar Muluk, and Enes Nusret Celik. The multidetector ct evaluation of diffuse hyperostosis frontalis interna. Romanian Journal of Rhinology, 14:117-124, Jul 2024. URL: https://doi.org/10.2478/rjr-2024-0018, doi:10.2478/rjr-2024-0018. This article has 0 citations.