Symptomatic subependymoma of the fourth ventricle. Case report.

Symptomatic subependymomas of the fourth ventricle are rare and usually not included in the preoperative differential diagnosis of tumors in this region. The case of a 63-year-old man with fourth ventricle subependymoma is described. For several years he had suffered with nausea and vomiting, and now presented signs of direct involvement of the posterior fossa. He was investigated preoperatively with computerized tomography, but the ultimate diagnosis was not suspected at that time. The tumor was diagnosed as an subependymoma at operation and was totally excised. This tumor type can easily be recognized on intraoperative frozen section, and its diagnosis should always lead to an attempt at complete surgical removal.