[Hemangiopericytoma: report of 4 cases]

Hemangiopericytoma is an infrequent tumor of vascular origin derived from Zimmermann's pericyte cells. It is generally seen in adults of both sexes and its major risk is late recurrence, that occurs in up to 50% of cases. Its spread pattern is principally hematogenous. The management of the disease is similar to that of other sarcomas. Surgical treatment alone controls the disease in less than 30% of cases and the association of surgery and radiation therapy decrease the risk of local and distant recurrence. We report four cases of hemangiopericytomas, located in the prostate, retroperitoneum, supraclavicular space and lung. The four patients were treated with surgery and radiation therapy, three of them have had no evidence of recurrence after 1.5 to 6 years of follow up and the patient with the tumor located in the lung died one year after the operation.