MUC1 and neoplasm: By immunostaining, the tumor cells were positive for alpha smooth muscle actin, h-caldesmon, muscle specific actin (HHF-35), laminin, type IV collagen, and vimentin, but negative for cytokeratin (AE1/AE3), epithelial membrane antigen (EMA), TTF-1, surfactant apoprotein A, S-100 protein, synaptophysin, and chromogranin A (Figures 3(a)–3(d)).