Differentiation of medulloblastoma

Abstract

A series of medulloblastomas was studied by light microscopy. The tumors were variable: astrocytic, ependymal, neuronal and probable oligodendroglial differentiation was present. Features of glioblastoma multiforme occurred in 1 case. Immunoperoxidase staining for glial fibrillary acidic protein (GFAP), an antigen found only in astrocytes and ependymal cells, revealed astrocytic differentiation in 11 of 13 cases. The 2 GFAP-negative tumors were histologically undifferentiated. A new classification of medulloblastomas is presented based on the multiple types of differentiation of these tumors. Neuronal, astrocytic, ependymal and small-cell types are described. Undifferentiated tumors were more frequent in younger children. The differentiation of medulloblastoma is correlated with recent experimental studies of gliogenesis and neurogenesis. A hypothesis that medulloblastoma is a stem-cell neoplasm is presented, based on these comparative data.