Extrarenal retroperitoneal angiomyolipoma.

Angiomyolipoma of the retroperitoneum is extremely rare with only 7 cases reported to date in the literature. Spontaneous hemorrhage and shock is the most common presentation that requires emergency intervention. We report a case of large extrarenal retroperitoneal angiomyolipoma that illustrates a different form of presentation for such a rare tumor mimicking a large locally advanced renal parenchymal tumor. The diagnosis was made by histopathology after performing radical nephrectomy. Although rare, angiomyolipoma of the perinephric fat may have variable presentations and should be considered in the differential diagnosis of large renal tumors particularly in view of possible kidney sparing management.