| Tumor type | WHO 2021 status / grade | Key molecular alterations | Characteristic histology / IHC markers | Typical age of onset | Common clinical presentation |
|---|---|---|---|---|---|
| Ganglioglioma | CNS WHO grade 1 | **BRAF p.V600E** most common; less often **FGFR1**, **KRAS**, **NF1**, **H3-3A/H3 K27M**, **RAF1** alterations; MAPK-pathway activation (pqac-00000012, pqac-00000014, pqac-00000023) | Dysmorphic neuronal cells with neoplastic glial component; eosinophilic granular bodies, lymphocytic infiltrates, CD34+ ramified cells; neuronal cells synaptophysin+/chromogranin A+; glial cells GFAP+/OLIG2+; Ki-67 usually <3% (pqac-00000023, pqac-00000024) | Usually childhood to young adulthood (pqac-00000005, pqac-00000003) | Long-standing focal epilepsy/seizures, often temporal lobe; headaches less common (pqac-00000003, pqac-00000005) |
| Dysembryoplastic neuroepithelial tumor (DNET) | CNS WHO grade 1 | **FGFR1** alterations in >75%; **BRAF p.V600E** in <1/3; MAPK-pathway altered (pqac-00000023, pqac-00000009) | Specific glioneuronal element with columns of oligodendroglia-like cells in myxoid matrix and “floating neurons”; Olig2+ oligodendroglia-like cells; floating neurons NeuN+/synaptophysin+ (pqac-00000023) | Usually children/adolescents and young adults (pqac-00000003) | Drug-resistant epilepsy, often cortical/temporal lesions (pqac-00000003, pqac-00000041) |
| Papillary glioneuronal tumor | CNS WHO grade 1 | **SLC44A1::PRKCA** fusion characteristic; occasional **PDGFRA** alterations reported (pqac-00000002, pqac-00000027) | Pseudopapillary / papillary architecture with GFAP+/S100+ glial lining cells and synaptophysin+/neuronal nuclear protein+ interpapillary neuronal elements; OLIG2+ oligodendrocyte-like cells may be present (pqac-00000027) | Mostly young adults (pqac-00000002) | Seizures and/or headaches from circumscribed supratentorial mass (pqac-00000002, pqac-00000003) |
| Rosette-forming glioneuronal tumor (RGNT) | CNS WHO grade 1 | **FGFR1** hotspot mutations, often with **PIK3CA**, **PIK3R1**, or **NF1** co-alterations (pqac-00000002, pqac-00000029) | Neurocytic rosettes and perivascular pseudorosettes with astrocytic component; neuronal cells synaptophysin+/MAP2+/NSE+; glial cells GFAP+/OLIG2+/S100+ (pqac-00000029) | Typically children/young adults (pqac-00000005, pqac-00000002) | Headache, ataxia, hydrocephalus, posterior fossa / fourth-ventricle symptoms rather than epilepsy (pqac-00000029, pqac-00000002) |
| Diffuse leptomeningeal glioneuronal tumor (DLGNT) | CNS WHO grade 1 in WHO 2021; methylation subclasses MC-1 and MC-2 described (pqac-00000001, pqac-00000006) | Frequently **KIAA1549::BRAF** fusion; also 1p loss and MAPK-pathway alterations; molecular subclassing by methylation clinically relevant (pqac-00000001, pqac-00000006, pqac-00000035) | Oligodendroglial-like cells in leptomeningeal/desmoplastic or myxoid background; OLIG2+, S100+, MAP2+ in oligodendroglial cells, GFAP+ astrocytic component (pqac-00000029) | Mainly pediatric, but can occur across ages (pqac-00000006, pqac-00000042) | Signs of diffuse leptomeningeal disease: hydrocephalus, cranial/spinal symptoms, multifocal neurologic deficits; epilepsy less typical (pqac-00000001, pqac-00000029) |
| Myxoid glioneuronal tumor (MGT/MGNT) | CNS WHO grade 1 | Recurrent **PDGFRA p.K385** mutation; DNT-like methylation profile (pqac-00000043, pqac-00000038) | Oligodendrocyte-like cells in prominent myxoid/mucin-rich stroma with floating neurons and sometimes neurocytic rosettes; strong MAP2/synaptophysin in neuronal component, often GFAP-negative (pqac-00000026, pqac-00000029, pqac-00000043) | Usually children and young adults (pqac-00000043) | Seizures or headaches; often septum pellucidum / periventricular lesion discovered on imaging (pqac-00000043, pqac-00000042) |
| Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC) | Provisional new type in WHO 2021 glioneuronal/neuronal family | Distinct methylation class; recurrent **monosomy 14** / chromosome 14 methylome abnormality (pqac-00000039, pqac-00000041, pqac-00000043) | Diffuse tumor with oligodendroglioma-like perinuclear halos and clustered nuclei; synaptophysin+/NeuN+/MAP2+/Olig2+, usually GFAP− or limited GFAP (pqac-00000025, pqac-00000030) | Predominantly pediatric / young patients (pqac-00000039, pqac-00000041) | Seizures and focal neurologic symptoms depending on cortical location (pqac-00000030, pqac-00000041) |
| Desmoplastic infantile ganglioglioma (DIG) | CNS WHO grade 1 | Molecular drivers less consistently defined than other entities; belongs to infantile glioneuronal spectrum in WHO 2021 (pqac-00000005, pqac-00000042) | Desmoplastic stroma with astroglial and neuronal/ganglion cell elements; glial cells GFAP+, neuronal cells synaptophysin+ (pqac-00000024, pqac-00000042) | Infancy, usually within first 2 years of life (pqac-00000005) | Macrocephaly, enlarging head circumference, seizures, signs of raised intracranial pressure from large superficial cystic/solid mass (pqac-00000005, pqac-00000042) |
| Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) | Pediatric-type diffuse low-grade glioma in WHO 2021 (not in glioneuronal family, but overlaps clinically/pathologically with LEATs) (pqac-00000039, pqac-00000042) | MAPK-pathway altered; **BRAF p.V600E**, **FGFR2/FGFR3** fusions and related FGFR-family alterations (pqac-00000006, pqac-00000030, pqac-00000043) | Oligodendroglioma-like / polymorphous infiltrative tumor; strong CD34 expression; strong MAP2 and synaptophysin, mostly GFAP-negative; may show perivascular pseudorosettes (pqac-00000030, pqac-00000043) | Children, adolescents, young adults (pqac-00000039, pqac-00000043) | Epileptogenic cortical tumor with chronic focal seizures (pqac-00000006, pqac-00000043) |
| Multinodular and vacuolating neuronal tumor (MVNT) | CNS WHO grade 1 | MAPK-pathway alterations reported; recognized as new WHO 2021 neuronal/glioneuronal-type entity (pqac-00000039, pqac-00000041) | Multinodular lesion composed of vacuolated neuronal cells; HuC/HuD+, OLIG2+, α-internexin+, weak/negative synaptophysin and neurofilament in some cells (pqac-00000028, pqac-00000026) | Often adults, but can occur across a wide age range (pqac-00000026, pqac-00000042) | Often incidental; may present with seizures or headaches (pqac-00000026, pqac-00000028) |
| Anaplastic ganglioglioma | CNS WHO grade 3 | May harbor **BRAF p.V600E** and occasionally **H3** alterations; MAPK-driven biology in subset (pqac-00000024, pqac-00000027) | Dysplastic neuronal cells plus anaplastic glial component, increased cellularity, pleomorphism, frequent mitoses, microvascular proliferation, necrosis; GFAP+/synaptophysin+/CD34+ pattern retained in components (pqac-00000024, pqac-00000027) | Children to adults (pqac-00000005, pqac-00000017) | Seizures, progressive focal deficits, mass effect; more aggressive course than grade 1 ganglioglioma (pqac-00000017, pqac-00000024) |
| Central neurocytoma | CNS WHO grade 2 | No single pathognomonic alteration routinely used in WHO; molecular heterogeneity reported (pqac-00000028, pqac-00000042) | Uniform round neurocytic cells with scant cytoplasm and neurocytic rosettes; synaptophysin+ and neuron-specific enolase+; OLIG2− (pqac-00000028) | Young adults (median around 30 years) (pqac-00000002) | Intraventricular mass causing headache, hydrocephalus, visual symptoms; seizures less common (pqac-00000002, pqac-00000028) |
| Extraventricular neurocytoma | CNS WHO grade 2 | **FGFR1::TACC1** fusion in about two-thirds in one series/reviewed cohort (pqac-00000002) | Neurocytic tumor outside ventricles; synaptophysin+ neuronal phenotype, similar to central neurocytoma but extraventricular location (pqac-00000002, pqac-00000042) | Young adults (median around 30 years) (pqac-00000002) | Seizures and headaches are common (pqac-00000002) |


*Table: This table summarizes major mixed neuronal-glial and closely related neuroepithelial tumor subtypes relevant to the WHO 2021 CNS classification, with practical emphasis on grade, molecular drivers, pathology, age, and presentation. It is useful as a quick reference for disease characterization and knowledge-base curation.*