Extrarenal retroperitoneal angiomyolipoma.

We describe a case of angiomyolipoma arising in the retroperitoneum and review other reported cases of extrarenal angiomyolipoma. We review the histologic characteristics of angiomyolipoma and describe our diagnostic evaluation. This case is the fifth reported occurrence of extrarenal retroperitoneal angiomyolipoma. In our case, as in the others, the correct diagnosis was made only after laparotomy, despite a number of preoperative imaging studies. Careful exploration should, in the future, result in more renal-sparing approaches.