Hemangiopericytoma of bone.

Primary hemangiopericytoma of bone is a rare malignant tumor. Forty-one cases from the literature were reviewed, and four additional cases are reported. The peak incidence is in fourth and fifth decades. The pelvis and lower extremities are the most common locations. The radiographic features are nonspecific, although angiography may aid in the diagnosis. Based on a limited number of evaluable cases, the prognosis seems to correlate with the histologic grade of the tumor. Late recurrence and distant metastases are common.