Sinonasal hemangiopericytoma: case report and literature review.

Hemangiopericytoma (HPC) is a rare vascular tumor that can arise in any organ system, but occurs most frequently in skeletal muscle. We present a case of a primary sphenoid sinus HPC unusual for its spontaneous remission after biopsy. There have been approximately 55 cases of sinonasal HPC reported in the literature, representing less than 5% of all lesions. In general, HPC behaves aggressively, demonstrating greater than 50% local recurrence and 10% metastatic disease. Although extended surgical resection is traditionally considered the most effective therapy for all HPC, critical literature review does not support this method of treatment for HPC occurring in the paranasal sinuses and skull base. Long-term follow-up indicates that the majority of sinonasal HPC have a benign clinical course regardless of treatment. As a result, we do not recommend extended resection as the initial therapy for sinonasal HPC. Instead, a period of observation coupled with serial MRI or CT scans should be used to detect tumor progression. These indolent tumors should undergo extended resection only after progression has been confirmed. In addition to the case report, a synopsis of the reviewed literature and a summary of treatment recommendations are also presented.