Contributions of immunohistochemistry to the problem of differentiation in medulloblastoma.

The problem of differentiation of medulloblastoma is considered. In this regard 43 medulloblastomas, showing cells with glial or neuronal features by routine histologic methods, were studied. The investigation was carried out by means of the immunohistochemical demonstration of the glial fibrillary acidic protein (GFAP) and the neuron-specific enolase (NSE). In most cases, GFAP-positive cells are preexisting astrocytes; in two cases they correspond to the transitional cells of the subependymal layer. NSE was demonstrated in areas filled with cells with neuroblastic features. The relationship between medulloblastoma with neuron-differentiation and cerebellar neuroblastoma is discussed.