Medullomyoblastoma: a case report.

Medullomyoblastoma is a rare childhood tumor of the central nervous system and there have been only seventeen cases reported in the English literature. A case of medullomyoblastoma arising from the cerebellar vermis was reported. Postmortem examination revealed diffuse leptomeningeal dissemination and supratentorial metastasis. In addition to classical histologic examination, the immunohistochemical and ultrastructural features were studied. Besides skeletal muscle differentiation, neither neuronal nor astrocytic differentiation were identified. The myoblastic element was confirmed by the demonstration of thick and thin myofilaments and Z bands on electron microscopy and by positive immunostaining for myoglobin.