“…Specifically, the malignant melanocytes can show different phenotypes (polyhedral, round, epithelioid, spindle-shaped or pleomorphic) and sizes (Barnes, 2000). They exhibit clear cytoplasm, round to oval nuclei, with one or more hyperchromic ("cherry red") or prominent nucleoli, and single cells can be found along the epithelium (in situ, invasive and combined pattern) or grouped in nests mainly below the interface (invasive and combined pattern), with or without the presence of seromucous glands (in situ pattern) and with intracellular melanin (Barnes, 2000;Coutinho-Camillo et al, 2016). Occasionally, due to the histological diversity of the lesion, auxiliary immunohistochemical (IHC) markers are required to identify S100, Mart1/Melan-A, MITF and HMB45 proteins, which are determinants to confirm the diagnosis of OMM (Table II) (Coutinho-Camillo et al, 2016;Smith et al, 2016;Feller et al, 2017;Topic´ et al, 2017).…”