PECAM1 and neoplasm: By immunohistochemistry, the tumor cells stained positively for S-100 (focal +), CD34 (strong +++), and Ki-67 (20%) (Fig. 2B–D), and negatively for smooth muscle actin, pan-cytokeratin (CK), neurofilament (NF), pan-cytokeratin-L, GFAP, CD31, STAT6, ERG, myogenin, and MyoD1.