Computed Tomography Evaluation of Retroperitoneal Hemangiopericytomas

Between January 1992 to December 1996, four patients with pathology-proven malignant retroperitoneal hemangiopericytomas were seen at our hospital. The clinical presentation, CT and pathological findings, treatment and outcome were reviewed. Two of the four hemangiopericytomas were found in abdominal retroperitoneum and the others in the pelvic retroperitoneum. The tumors were shown to have smooth margin, tended to be large (three of them were larger than 14 cm in its longest dimension) enough to displace but not invade the adjacent organs. The two abdominal hemangiopericytomas and one of the pelvic hemangiopericytomas showed heterogeneous enhancement with necrotic components in enhanced CT scan, the other one of pelvic hemangiopericytomas showed strong homogeneous enhancement without obvious necrotic component. In none of the patients, regional lymph node or intraabdominal metastasis was shown in the CT study. No recurrence was found in all of the patients followed up to 5 years after surgery. Although hemangiopericytoma is a rare disease, it should be considered when a huge encapsulated retroperitoneal mass with strong enhancement and necrotic components is shown in CT scan study