Synonyms and classification:
- Gangliocytoma, WHO grade I
- Ganglioglioma WHO grade I or II a.k.a. ganglion cell tuomur
Diagnosis:
Suggested by MRI and confirmed by pathology (brain biopsy/resection)
Findings on Investigations:
May occur through out the CNS. Commonly temporal lobe. Circumscribed solid mass or cyst with mural nodule.
CT: hypodense or isodense. Calcification may occur.
MRI:
- T1: hypointense
- T2: hyperintense
- Enhancement: variable
Pathology:
Histology: Neoplastic mature ganglion cells (abnormal e.g. binucleate, lack of polarity, nuclear pleomorphism, clustered in groups). If alone= gangliocytoma. If with neoplastic glial cells= ganglioglioma. Eosinophilic granular bodies, Perivascular lymphocytic cuffing, cystic spaces & calcifications may occur.
Gangliocytoma: groups of large, irregular multipolar neurons. Non-neoplastic glial stroma. Reticulin fibre network.
Ganglioglioma: as in gangliocytoma except there is a neoplastic glial component, usually astrocytic. Necrosis is absent.
Immunohistochemsitry: GFAP usually positive in ganglioglioma. Ganglion cells are positive for neural markers e.g. synaptophysin, neurofilament, chromogranin. Neoplastic neurons are NeuN negative. MIB low.