Hemangiopericytoma in the Olfactory Groove: A Rare and Unusual Presentation.

Intracranial hemangiopericytomas (HPCs) are solitary fibrous tumors of the smooth muscle and the mesenchymal origin. While meningiomas located within the olfactory groove are common, an HPC in this location has never been reported previously. Here we describe the rare presentation of a differentiated HPC masquerading as an olfactory groove meningioma in a 33-year-old female presenting with the progressive headaches, anosmia, and visual field disturbances. Following resection, the histopathological analysis confirmed a grade II HPC. A preoperative understanding of the radiographic differences between the meningiomas and HPCs may confirm the treatment planning. An HPC must be considered in the differential diagnosis of the tumors located within the olfactory groove.