MUC1 and neoplasm: Immunohistochemically, the tumor cells were strongly positive for vimentin and calretinin (Figure 4A,B), moderately positive for CD99 and epithelial membrane antigen (EMA) (Figure 4C,D), partially positive for cytokeratin and Ki67 (Figure 4E,F), but negative for actin, S-100, desmin, and HMB45.