[Renal angiomyolipoma: a cause of massive retroperitoneal hemorrhage]

Five patients were diagnosed as having angiomyolipoma. Evidence or signs of tuberous sclerosis were observed in no patient. In 2 patients the presenting symptoms was massive retroperitoneal hemorrhage which required emergency surgery. The kidney could be preserved in 4 cases. One underwent nephrectomy for synchronous clear cell renal tumor. CT and US afford a diagnostic accuracy of nearly 100 percent. According to the data reported in the literature, tumors larger than 4 cm are amenable to treatment by conservative surgery. Smaller tumors can be followed carefully. However, surgical exploration is warranted not only in patients with pain and hemorrhage, but also in those cases with complex lesions less than 4 cm.