MUC1 and chondrosarcoma: Immunohistochemically, chondrosarcoma cells were strongly and diffusely positive for S100 (both nuclear and cytoplasmic staining; Fig. 2A), vimentin, epithelial membrane antigen (EMA; Fig. 2B), and focally immunoreactive with CAM 5.2 (Fig. 2C) and cytokeratin (CK) AE1/AE3.