Extra-adrenal myelolipoma with hemolytic anemia.

Myelolipomas are rare benign tumors often detected as adrenal masses. Extra-adrenal myelolipomas are encountered even more rarely. The rate of detection of these lesions is increasing with improved radiological techniques. Because of their localization and morphological similarities to well differentiated liposarcomas, extra-adrenal myelolipomas need to be differentiated from other aggressive neoplasms. Preoperative imaging and percutaneous biopsy are important tools in the diagnosis of these lesions. We report a very rare case of an extra-adrenal perirenal myelolipoma associated with hemolytic anemia. The etiology, differential diagnosis, and treatment options for the lesion have been discussed. Fat-containing tumors of the retroperitoneum should be considered in the differential diagnosis. Accurate diagnosis is important to avoid over-treatment of these benign lesions.