MR appearance of pelvic hemangiopericytoma.

A case of pelvic hemangiopericytoma in a 59-year-old woman is reported. The MR imaging features are presented. The tumor was unresectable and the patient received postoperative irradiation of 4200 cGy on the pelvis. One year after diagnosis, metastasis to a lumbar vertebra was discovered and additional irradiation of 3900 cGy was applied. One year later, CT showed control of the pelvic tumor and its metastasis.