Diffuse meningeal rhabdomyosarcoma.

Pure rhabdomyosarcomas are extremely rare as primary tumors in the cranial vault. In this instance, a 25-year-old man had symptoms and signs of chronically increased intracranial pressure. A biopsy of the meninges of his posterior fossa was performed revealing a spindle-cell sarcoma. Ultrastructural evidence of striated muscle differentiation and cross striations was present. The patient died of pulmonary emboli. Complete autopsy failed to disclose tumor anywhere except the leptomeninges. The presence of this tumor indicates that a rhabdomyosarcoma can arise from the meninges without a preexisting glioma or teratoma.