Tomlinson, Frank H.

Abstract A unique gliomesenchymal neoplasm, consisting of a subependymoma, a form of low-grade glioma, and a rhabdomyosarcoma, is described. It arose and recurred in the brain stem of a 52-year-old man. Immunohistochemical studies demonstrated the presence of a neuroectodermal marker S-100 protein within some sarcoma cells. The occurrence of this rare tumor supports the concept that striated muscle may derive from a neuroectodermal precursor lesion.

The pathobiology of medulloblastoma is reviewed in light of emerging data regarding its immunocytochemical and cytobiologic, as well as molecular biologic, characteristics. The nature of the lesion, particularly its nosologic relation to primitive neuroectodermal tumor, is discussed, as is its place in the World Health Organization classification of tumors of the central nervous system. ( J Child Neurol 1992;7:240-252).

Medulloblastoma, the most common embryonal tumor of the central nervous system, affects both children and adults. It poses a significant therapeutic challenge in that age-dependent differences exist, not only in their pathobiology, but in the efficacy of chemotherapy and radiotherapy. This is particularly the case in very young children, whose still developing nervous system exhibits a low tolerance to radiotherapy. We review the epidemiology, clinical presentation, radiologic features, and current therapeutic concepts relative to this unique neoplasm. Efforts are made to highlight clinical controversies. ( J Child Neurol 1992;7:142-155).