 Immunohistochemical evidence of neuronal differentiation is found in nearly all cases with neuronal markers such as synaptophysin, neuronspecific enolase, and neurofilament protein.Some medulloblastomas may also display other forms of differentiation as demonstrated by the presence of the astrocytic marker glial fibrillary acidic protein.Skeletal muscle and melanocytic differentiation are considerably less common and define the medullomyoblastoma and melanotic medulloblastoma variants, respectively.