Malignant hemangiopericytoma of the bone

Hemangiopericytoma is a rare vascular tumor of pericyte origin with variabl e malignant potential. Very rarely, this tumor occurs as a primary bone les ion. We present a case of a highly malignant hemangiopericytoma of the prox imal tibia. Current therapy consists of radical resection of the tumor with postoperative radiation therapy being recommended. Chemotherapy seems to b e useful in disseminated disease. The prognosis correlates to the histologi cal grading of the tumor. Early or late recurrence and distant metastases w ith fatal outcome, as shown in our case study, are not uncommon.