CNS & pituitary tumors

Gliomas, glioneuronal tumors and neuronal tumors

Neuronal and mixed neuronal-glial tumors

Gangliocytoma & ganglioglioma

Editorial Board Member: Meaghan Morris, M.D., Ph.D.
Deputy Editor-in-Chief: Chunyu Cai, M.D., Ph.D.
Jared T. Ahrendsen, M.D., Ph.D.

Last author update: 19 December 2022
Last staff update: 11 October 2023

Copyright: 2002-2024,, Inc.

PubMed Search: Gangliocytoma & ganglioglioma

Jared T. Ahrendsen, M.D., Ph.D.
Page views in 2023: 16,123
Page views in 2024 to date: 8,205
Cite this page: Ahrendsen JT. Gangliocytoma & ganglioglioma. website. Accessed July 13th, 2024.
Definition / general
  • Uncommon, well differentiated, slow growing glioneuronal tumors composed predominantly of neoplastic mature ganglion-like cells (gangliocytoma) or a mixture of neoplastic ganglion-like cells and atypical glial cells (ganglioglioma)
Essential features
  • Ganglioglioma and gangliocytoma are considered discreet tumor entities by the 2021 WHO classification of CNS tumors
  • Neoplastic ganglion cells often display dysplastic / dysmorphic features
  • Characterized by molecular alterations resulting in activation of the MAPK pathway (BRAF V600E is most common)
  • Commonly associated with epilepsy
ICD coding
  • No known risk factors or environmental exposures for ganglioglioma or gangliocytoma
Clinical features
  • Magnetic resonance imaging (MRI) of brain
  • Stereotactic biopsy can be performed, especially in sites unamenable to surgical excision
Radiology description
  • Circumscribed, cystic mass with enhancing mural nodule
  • Classically, well delineated, T1 hypointense, T2 hyperintense cyst with enhancing mural nodule (Radiographics 2002;22:1177)
  • Variable calcifications and enhancement
Radiology images

Contributed by Jared T. Ahrendsen, M.D., Ph.D.

Temporal lobe mass

Prognostic factors
Case reports
Gross description
  • Well demarcated, variably solid and cystic mass forming lesion
  • Lacks areas of hemorrhage and necrosis
Frozen section description
  • Well demarcated mass but can show brain infiltration at the tumor edge
  • Admixture of neuron-like cells and atypical glial cells (ganglioglioma) or predominantly neuron-like cells (gangliocytoma)
  • Variable microcalcifications, perivascular lymphocytes, eosinophilic granular bodies
  • Reference: Acta Cytol 2022;66:142
Intraoperative frozen / smear cytology images

Contributed by Jared T. Ahrendsen, M.D., Ph.D.

Low grade glioneuronal tumor

Admixture of mildly atypical glial cells

Microscopic (histologic) description
  • Ganglioglioma:
  • Gangliocytoma:
    • Generally similar to that of ganglioglioma except lacking atypical neoplastic glial cells
    • Composed almost entirely of large, dysmorphic ganglion cells (as described above), often arranged in irregular clusters
Microscopic (histologic) images

Contributed by Jared T. Ahrendsen, M.D., Ph.D.

Well circumscribed brain lesion

Mixed glioneuronal tumor

Ganglioglioma with binucleate neurons

Well demarcated mass

Dysplastic ganglion-like cells in gangliocytoma

Olig2 IHC


Synaptophysin IHC

Virtual slides

Images hosted on other servers:
Circumscribed glioneuronal tumor

Circumscribed glioneuronal tumor

Positive stains
Negative stains
  • Ganglion-like cells often lack NeuN immunoreactivity (which is positive in nonneoplastic neurons)
  • Negative for IDH1 R132H staining
Electron microscopy description
  • Not routinely used for clinical / diagnostic purposes
  • Ultrastructural characteristics of ganglioglioma include:
    • Ganglion-like cells with numerous dense core granules within the perikarya and cellular processes and abundant rough endoplasmic reticulum (Cancer 1997;79:989)
Molecular / cytogenetics description
  • Ganglioglioma:
  • Gangliocytoma:
    • No signature molecular profile published to date

Neuronal and glioneuronal tumors
by Dr. Fausto Rodriguez (PathCast)

Sample pathology report
  • Brain mass, temporal lobe, resection:
    • Ganglioglioma, BRAF V600E mutant, WHO grade 1
    • Histologic classification: ganglioglioma
    • WHO grade: 1
    • Molecular information: BRAF V600E
Differential diagnosis
Board review style question #1

A 15 year old patient presents with chronic seizures that are refractory to medical management. Magnetic resonance imaging (MRI) of the brain reveals a cystic lesion with an area of solid enhancement located in the medial temporal lobe. Surgical resection was performed, revealing the histology shown above. What is the most likely diagnosis?

  1. Ganglioglioma
  2. Glioblastoma
  3. Oligodendroglioma
  4. Pilocytic astrocytoma
  5. Subependymal giant cell astrocytoma
Board review style answer #1
A. Ganglioglioma. This clinical scenario describes classic features of ganglioglioma: a young patient with refractory seizures who presents with a cystic mass with enhancing mural nodule and histology that demonstrates a biphasic tumor with admixed neoplastic glial cells and dysmorphic ganglion-like cells. Other common histologic findings include perivascular lymphocytes, calcifications and eosinophilic granular bodies. Glioblastoma (answer B) is a high grade, infiltrating neoplasm composed of markedly atypical glial cells with increased mitoses, necrosis and microvascular proliferation. Oligodendroglioma (answer C) generally occurs in adults with brain imaging that shows an infiltrative process and histologic examination that reveals tumor cells with perinuclear halos (fried egg appearance). Pilocytic astrocytoma (answer D) usually occurs in the cerebellum or optic pathway and is characterized by bipolar glial cells with hair-like (piloid) processes, Rosenthal fibers, eosinophilic granular bodies and degenerative atypia. Subependymal giant cell astrocytoma (answer E) is a tumor found almost exclusively in patients with tuberous sclerosis; it is generally located near the ventricles and is composed of large, atypical, multinucleated astrocytes without a population of neoplastic ganglion-like cells.

Comment Here

Reference: Gangliocytoma & ganglioglioma
Board review style question #2
A 10 year old patient with chronic epilepsy underwent surgical resection of a temporal lobe mass. The histology was compatible with ganglioglioma, WHO grade 1. What is the most likely molecular alteration present in this tumor?

  1. BRAF V600E mutation
  2. H3 K27M mutation
  3. IDH1 R132H mutation
  4. NF1 mutation
  5. NF2 mutation
Board review style answer #2
A. BRAF V600E mutation. This is the most common alteration observed in ganglioglioma. H3 K27M mutation (answer B) is a characteristic molecular alteration of diffusely infiltrating midline gliomas (such as diffuse intrinsic pontine glioma). IDH1 R132H (answer C) is the most common IDH mutation, which occurs in oligodendrogliomas and infiltrating astrocytomas. NF1 alterations (answer D) are commonly seen in pilocytic astrocytomas of the optic pathway (i.e., optic pathway glioma). NF2 mutations (answer E) are common in meningiomas and schwannomas

Comment Here

Reference: Gangliocytoma & ganglioglioma
Back to top
Image 01 Image 02