The clinical and radiologic manifestations of hemangiopericytoma.

The clinical and radiologic findings in nine patients with hemangiopericytoma were reviewed. There were eight women and one man with a mean age of 46 years. Seven of the neoplasms, including two locally recurrent tumors, were in the pelvis and two were in the thigh. Conventional radiographs were available for all patients. Five patients were evaluated by sonography, four by CT, three by angiography, and two by MR imaging. There was evidence of compression of adjacent viscera by six of the seven pelvic tumors with associated hydronephrosis in one patient. One thigh lesion had focal areas of speckled calcification. All five neoplasms evaluated by sonography showed a well-circumscribed hypoechoic lesion and three had significant sound through-transmission. Hypervascularity was documented by contrast-enhanced CT or angiography in each of three patients in whom these procedures were performed. Surgical resection of the pelvic neoplasms was complicated by marked hemorrhage. Hemangiopericytoma should be considered in the differential diagnosis of well-circumscribed hypervascular tumors in a middle-aged patient.