This is a 9 cm. mass in the uterine fundus which nearly completely replaces the anterior myometrium. Although the cut surface is firm, it has a distinct yellow, glistening appearance with a slightly "greasy" feel. The tumor bulges away from the thin rim of remaining surrounding myometrium. Of note, the surface is lobulated and does not appear "whorled" as would be seen in a typical leiomyoma. Microscopically, these tumors show an admixture of mature adipocytes and smooth muscle cells. At times, anomalous blood vessels may be present raising the differential diagnosis of angiolipoleiomyoma.

Usually found in the uterine fundus, these tumors can also occur in the cervix. They are often found in association with leiomyomas. The patient is likely to be menopausal or postmenopausal and is often obese. The patients are often asymptomatic but can present with any of the symptoms associated with leiomyomas. The fat in lipoleiomyomas is thought to result from “lipomatous” metaplasia of the smooth muscle cells in a leiomyoma.

Contributed by Dr. Dan Koelliker.