Catamenial Pneumothorax: Research Report

Verification status. Only the PMIDs and URLs listed under "Sources actually retrieved" came from searches in this session, and I did not open the full texts or check abstract quotes. Everything else is from background knowledge of the literature and is marked (unverified). Do not cite those items in the KB until they have been fetched with just fetch-reference and quoted exactly. I did not verify any ontology CURIEs. HP, GO, CL, UBERON and NCIT lookups are still needed, and the MONDO ID in the request (MONDO:0022098) is unconfirmed.

1. Disease information

Catamenial pneumothorax (CP) is a recurrent spontaneous pneumothorax that occurs within about 72 hours before or after the onset of menstruation. It mostly affects women of reproductive age. Most cases are attributed to thoracic endometriosis syndrome (TES). A recent review describes it as "an uncommon condition, usually associated with thoracic endometriosis syndrome (TES)" and notes that international guidelines are still lacking (PMC11728258).

• Synonyms: menstrual pneumothorax, endometriosis-related pneumothorax. It is the commonest manifestation of TES. The others are catamenial hemothorax, catamenial hemoptysis, and pulmonary endometriosis nodules.
• Identifiers: I did not confirm OMIM, Orphanet, ICD-10/11 or MeSH entries. ICD-10 N80.8 (other endometriosis) is a plausible fit (unverified). The search tool only reached the NCBI MedGen page (C0340007) and did not retrieve its contents.
• Lump/split note for dismech: CP is a clinical presentation of TES, not a separate pathogen-defined disease. Consider whether it belongs as a DISEASE entry, as a subtype of thoracic endometriosis or endometriosis, or as a GROUPING member. Record the decision in the stub notes.
• Data source: The evidence is aggregated case series and case reports. It does not come from EHR-derived cohorts.

2. Etiology

• Causal factors: There is no single causal gene or exposure. The leading mechanisms are thoracic endometriosis (diaphragmatic, pleural or parenchymal) and passage of air through diaphragmatic defects. Lung blebs or bullae and hormonal effects are other proposed contributors.
• Risk factors:
• Pelvic endometriosis. CP can be the first presentation of both thoracic and pelvic disease (Ciriaco et al., PMID 35268286).
• Reproductive age.
• Prior uterine or pelvic surgery (unverified).
• Genetic susceptibility is not established.
• Protective factors: Ovarian suppression by GnRH analogues or hormonal contraception reduces recurrence once the disease is present. These are treatments, not primary protective factors.
• Gene-environment interactions: None are established.

3. Phenotypes

Frequencies below are approximate and from memory (unverified). They need to be traced to primary series, such as the Joseph & Sahn and Visouli et al. reviews.

• Onset: Typically the 30s to 40s (unverified). Onset is acute and episodic, and episodes recur with the cycle.
• Quality of life: Repeated hospitalizations and drainage procedures, and diagnostic delay. The sources I found did not give formal QoL instrument data.

4. Genetic and molecular information

No causal genes or pathogenic variants are established. I found no evidence for a Mendelian cause, so do not create genetic: causal rows without a source. Endometriosis itself has polygenic susceptibility (GWAS loci), but I did not verify any specific locus for thoracic disease. There is no chromosomal or epigenetic data in what I retrieved.

5. Environmental information

There are no established environmental, lifestyle or infectious factors. The relevant trigger is endogenous: the menstrual cycle.

6. Mechanism / pathophysiology

Proposed causal chains (the search results name four theories: physiological, migrational, microembolic-metastatic, and the diaphragmatic theory of air passage):

1. Diaphragmatic air-passage branch (anatomical).
2. Diaphragmatic fenestrations are present, usually right-sided.
3. During menses the cervical mucus plug is absent.
4. Air passes from the genital tract into the peritoneal cavity.
5. Air crosses the diaphragmatic fenestrations into the right pleural space.
6. The result is pneumothorax at menses.
7. This is a proposed pathway, not demonstrated in all patients. It is the usual explanation when no thoracic endometriosis is found.
8. Thoracic endometriosis branch.
9. Endometrial tissue reaches the diaphragm or pleura. The route is proposed to be retrograde menstruation with transperitoneal passage, or microembolic or lymphovascular spread. This is inferred, not shown.
10. Ectopic endometrial implants respond to cyclic hormones.
11. Menstrual shedding at the implants causes the diaphragmatic perforation or visceral pleural/parenchymal disruption.
12. Air enters the pleural space, and pneumothorax follows.
13. Hormonal/prostaglandin branch.
14. Prostaglandin F2α rises at menses.
15. It is proposed to cause bronchiolar constriction, especially in expiration.
16. Alveolar rupture follows and traps air in the pleural space.
17. This is a hypothesis. The search summary describes it as a theory only.
18. Bleb rupture branch. Cyclic hormonal changes are proposed to cause spontaneous bleb rupture. This is weakly supported.

Suggested ontology terms (all need lookup before use):

• GO: response to estradiol, response to progesterone, prostaglandin biosynthetic process.
• CL: endometrial stromal cell, endometrial epithelial cell.
• UBERON: diaphragm, parietal pleura, visceral pleura, pleural cavity, right lung.
• CHEBI: prostaglandin F2α.

No molecular profiling, single-cell or CRISPR data were found.

7. Anatomical structures affected

• Primary: Right hemidiaphragm, pleura and pleural space, and lung. Right-sided predominance is widely reported (unverified figure).
• Secondary: Pelvic organs, because endometriosis often coexists.
• Tissue and cell level: Ectopic endometrial glands and stroma on the diaphragm or pleura.
• Lateralization: Predominantly right-sided and usually unilateral.

8. Temporal development

• The course is recurrent and cyclical, with episodes clustering around menses.
• Without definitive treatment, recurrence is frequent. Chest tube drainage alone carries a recurrence rate of up to 50% according to the search summary.
• Remission occurs during ovarian suppression, pregnancy, or after menopause (unverified).

9. Inheritance and population

• It is not a Mendelian disease, and no inheritance pattern is established.
• It is rare. I could not source prevalence or incidence figures.
• It affects only people with a menstrual cycle, with onset mostly in the reproductive years.
• Diagnostic delay is likely, because the cyclical pattern is missed. Reviews describe it as an "unveiled disease" (PMC11728258).

10. Diagnostics

• Clinical criterion: Pneumothorax recurring within 72 hours of menses, with a cyclical history (unverified criterion).
• Imaging: Chest X-ray, and CT, which can show diaphragmatic defects or nodules. Pelvic and thoracic MRI can help detect endometriosis. Timing the imaging to menses improves the yield (unverified).
• Thoracoscopy: VATS allows direct inspection of the diaphragm for perforations or implants. It is also the route for biopsy, with histology showing endometrial glands and stroma. Immunohistochemistry (ER, PR, CD10) is supportive (unverified).
• Differential diagnosis: Primary spontaneous pneumothorax, lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, and other causes of cystic lung disease.
• Genetic testing: Not applicable for typical CP. FLCN testing is relevant only where cystic lung disease or Birt-Hogg-Dubé syndrome is a differential.

11. Outcome and prognosis

• Recurrence depends on the treatment. Surgery followed by prompt hormonal therapy gave no recurrence in the series summarized in the search. One patient had a recurrence when hormone therapy was delayed by 6 weeks (from search summaries; I did not read the underlying papers).
• Mortality is very low, and complications relate to repeated pneumothorax and procedures. I found no sourced survival data.
• Prognostic factors: completeness of surgical treatment and adherence to hormonal suppression.

12. Treatment

• Acute episode: Chest tube drainage. Recurrence after drainage alone is high, up to 50% per the search summary.
• Hormonal therapy:
• GnRH analogues for 6–12 months are described as the broad consensus for preventing recurrence. They induce hypogonadotropic hypogonadism and amenorrhea.
• Oral contraceptives, progestins and danazol have been used (unverified).
• Candidate NCIT terms: Pharmacotherapy NCIT:C15986, with therapeutic_agent for leuprolide or other agents. Look up each agent in CHEBI/NCIT.
• Surgery:
• VATS inspection of the diaphragm.
• Mechanical pleurodesis.
• Repair of diaphragmatic defects, with or without mesh.
• Resection of implants or blebs.
• Candidate NCIT: Surgical Procedure NCIT:C15329. A thoracoscopic-surgery term may exist and needs checking.
• Combination of VATS plus postoperative hormonal therapy gives the best outcomes, per the search summary.
• Multidisciplinary care: Thoracic surgery, gynecology and pulmonology (PMC11728258).
• Pharmacogenomics, gene/cell/RNA therapies and clinical trials: None found. I did not search ClinicalTrials.gov.

13. Prevention

• There is no primary prevention.
• Tertiary prevention is hormonal suppression after surgery, started promptly.
• Early recognition of the menstrual pattern could shorten diagnostic delay.

14. Other species / natural disease

No naturally occurring animal disease was identified. This section is not applicable on the evidence I retrieved. I did not query OMIA.

15. Model organisms

I found no established animal model of catamenial pneumothorax. Endometriosis models exist in mouse and primate, but I did not verify any that reproduce thoracic disease. Treat this section as a gap, and consider a KNOWLEDGE_GAP discussion rather than an animal_models: entry.

Curation recommendations

1. Fetch the references below with just fetch-reference PMID:<id> and quote only exact substrings.
2. Locate the primary large-series sources for laterality, age, frequency and recurrence figures, and for the TES component percentages. Do not rely on my recalled numbers.
3. Verify the MONDO ID, and decide the lump/split question first.
4. Run just check-causal-targets and wire the phenotypes. Unconnected phenotypes would be a likely weakness in this entry.

Sources actually retrieved

• Catamenial Pneumothorax—Still an Unveiled Disease (PMC11728258)
• Ciriaco et al., Catamenial Pneumothorax as the First Expression of Thoracic Endometriosis Syndrome and Pelvic Endometriosis, J Clin Med 2022. PMID 35268286
• Hirono et al., Spontaneous recurrent menstrual pneumothorax: a case report, Ann Med Surg. PMID 38333324
• Tsakiridis et al., Catamenial pneumothorax recurrence due to endometriosis, Respir Med Case Rep 2020. PMID 32190546
• Multi-Loculated Catamenial Pneumothorax: A Rare Complication of Thoracic Endometriosis
• Other pages surfaced by the searches but not read: Wikipedia, Respiratory Care, NORD, IntechOpen chapter, MedGen.

Reference Validation

Checked with linkml-reference-validator 0.3.0rc3.

3 of 8 references resolved; the rest could not be looked up either way.

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Every term resolved, and every label the report gave matched.