Hemangiopericytoma of the maxillary sinus and skull base.

Since 1949, only 52 cases of hemangiopericytoma (HPC) of the nose and paranasal sinuses have been reported in the literature. Of the latter, only 2 originated from the maxillary sinus. This article reports 2 new cases. One arose in the maxillary sinus and involved the pterygopalatine fossa, skull base, and infratemporal fossa. The second tumor was located in the sphenoethmoidal recess. A new combination of techniques for resection of hemangiopericytoma of the skull base is described. Prognostic criteria for such tumors are reviewed, in conjunction with histological diagnosis.