SOX10 and malignant myoepithelioma: Myoepithelial carcinomas usually have moderate to severe atypia or pleomorphism with prominent nucleoli, high mitotic count, and necrosis. The tumor cells in myoepithelial tumors of soft tissue are usually positive for keratin AE1/AE3, EMA, S100, calponin, and variably positive for GFAP, smooth muscle actin, SOX10, and p63 [7,8].