Hemangiopericytoma of the third ventricle. Case report.

The authors present the first reported case of a hemangiopericytoma (HPC) occurring in the third ventricle. Most of these lesions are based in the meninges. There is only one other reported case of an intraventricular HPC; in that case the lesion was found in the lateral ventricle. A 40-year-old right-handed man presented with a 3-month history of headaches. Clinical evaluation, including computerized tomography and magnetic resonance imaging studies, revealed a 1-cm enhancing lesion in the third ventricle. Given the findings on the preoperative imaging studies, the lesion was not consistent with some of the more commonly occurring tumors of the third ventricle, namely colloid cysts. A transcortical approach and resection of the lesion was performed without complication. The final pathological findings were consistent with those of an HPC. Hemangiopericytomas rarely occur in the ventricles and may pose a difficult diagnostic dilemma based on their radiographic and gross appearances, as shown in this case. Because of this difficulty, histological confirmation is required to make a definitive diagnosis. These lesions have a propensity to recur and metastasize in the central nervous system and periphery, thus making the goal of treatment a complete surgical resection followed by postoperative radiation therapy in most cases.