Sudden unexpected death resulting from previously nonsymptomatic subependymoma.

A 34-year-old, previously healthy man died suddenly and unexpectedly. The autopsy showed brain and pulmonary edema, numerous small meningeal meningiomas, bilateral and symmetrical juxtaventricular meningiomas, and a well-demarcated gray tan tumor in the medulla oblongata and upper cervical spinal cord. The latter tumor was a subependymoma with features of ependymoma in places. The authors describe and discuss the characteristics of this rare central nervous system tumor, its histogenesis, and its coexistence with other intracranial tumors. The possible mechanisms of death in the present case include compression of vital centers and acute obstruction of the cerebrospinal fluid flow.