Angiomyolipoma in the knee--a case report.

Extrarenal angiomyolipoma is an uncommon disease and this may be the first report of angiomyolipoma in the knee, mimicking a malignant sarcoma. A 38-year-old man without tuberous sclerosis presented with a history of increased mass in the knee joint. Computerized tomography and magnetic resonance imaging demonstrated a CS x CS x CR cm subcutaneous tumor in the knee joint. The tumor was widely excised. Histologically, the tumor was, well circumscribed, and composed of smooth muscle, vascular spaces, connective tissue, and mature fat. There were no signs of recurrence at one year and eight months after surgery.