A case of retroperitoneal lipoleimyoma

We report a case of lipoleiomyoma which arose in retroperitoneum and presen ted with progressively distended abdomen in a 56-yr-old woman. The tumor wa s well encapsulated and consisted of two components, benign smooth muscle c ells and mature adipose tissue without any atypia. It is likely to be mista ken as extrarenal angiomyolipoma, well-differentiated liposarcoma and leiom yoma with fatty change. We review the histologic characteristics of previou sly reported myolipoma and describe essential points of differential diagno sis.