CD99 and undifferentiated pleomorphic sarcoma: Expression of CD10, CD99, CD68 (focal) and smooth muscle actin (focal), S100 protein, melan-A, desmin, CD34, p63, CD31, and human herpesvirus latent nuclear antigen 8 were markers also identified in atypical fibroxanthoma [31], together with the presence of hyperchromatic cells described both in atypical fibroxanthoma [31] and in undifferentiated pleomorphic sarcoma [41].