MUC1 and neoplasm: In our case, the tumor cells were positive for SMA (strong and diffuse), calponin (strong and diffuse), and HHF35, which are muscle antigens, and negative for pan-cytokeratin (AE1AE3), CK18 and EMA (all epithelial markers), s100 (neural/melanocytic marker), and CD31, CD34, ERG, and FLI1 (all endothelial/vascular markers).