Abstract: Unstained sections from formalin-fixed, paraffln-embedded specimen were observed under fluorescent microscope. Nine of 10 primary cutaneous melanomas and one of 2 metastatic melanomas were positive for yellowish green fluorescence. Two of 15 nevocellular nevi were also postive. Various other cutaneous tumors examined showed negative result.This yellowish green fluorescence, which is characteristic for melanoma, can be easily demonstrated and may be used in diflerentisting melanoma cells from other cutaneous tumor cells.