MUC1 and perineurioma: The lesion's immunohistochemistry (IHC) revealed that it was positive for epithelial membrane antigen (EMA) (Figure 7) but negative for S-100, CD34, desmin, and smooth muscle actin, ruling out schwannoma, dermatofibrosarcoma protuberans, and myoepithelial tumors, and was typical of extraneural perineurioma.