Immunochemical analysis displayed the tumor cells were diffusely positive for HMB45 (Fig. 5A) and CD34 (Fig. 5B), patchily stained for Melan-A (Fig. 5C); they were negative for Vimentin, CD1a, pan cytokeratin cocktail AE1/AE3, cytokeratin 7, cytokeratin 20, epithelial membrane antigen (EMA), thyroid transcription factor-1, smooth muscle actin (SMA), synaptophysin (Syn), chromogranin (CgA) and S-100. This evidence concerns the gene PMEL and neoplasm.