Epithelioid Angiomyolipoma : SMA
Section Editor: Dharam M. Ramnani, MD
Virginia Urology, Richmond, VA, USA
Image Description
Angiomyolipoma - Immunohistochemistry: Immunohistochemical stains are not necessary in classic triphasic tumors. In unusual morphologic variants (e.g. epithelioid AML), they may be extremely helpful. Angiomyolipomas are positive for melanocytic markers (HMB-45, Melan-A/MART-1) and smooth muscle actin and negative for cytokeratins, CD10, and EMA. The image shows smooth muscle actin immunoreactivity in an epithelioid angiomyolipoma. Renal cell carcinomas are usually positive for EMA/MUC1, CD10, CA9 and cytokeratins and negative for melanocytic markers such as HMB-45 and Melan-A.