9474/3 Large cell medulloblastoma


Definitions

Tumours of the central nervous system
ICD-O-3 topography code: C70, C71 and C72
ICD10: C71.6
           

Large cell medulloblastoma is a rare variant of medulloblastoma, characterized by monomorphic tumour cells with large, round, vesicular nuclei, prominent nucleoli and variable amount of eosinophilic cytoplasm. Mitotic and apoptotic figures are abundant. Amplification of MYCC or MYCN is an infrequent, but typical genetic alteration.
Large cell medulloblastoma represents approximately 2?4% of medulloblastomas, has a marked tendency for CSF metastases and carries worse prognosis than the classic medulloblastoma 1
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



.
Large cell and anaplastic medulloblastoma have considerable cytological overlap.