Dermatoscopic and videomicroscopic features of melanocytic plantar nevi.

Nearly 10% of Japanese people have pigmented nevi on the soles. Since malignant melanoma also occurs on the plantar area in the Japanese, it would be very valuable to be able to differentiate benign and malignant lesions in the early clinical state. We have investigated the epiluminescence microscopic features of 500 melanocytic nevi on the soles of Japanese people using a dermatoscope and a videomicroscope that can magnify lesions from x 10 to x 200. The results showed that the surface profile of benign melanocytic nevi is mainly classified into five types; that 9% of plantar nevi, however, do not fit into this classification and are categorized as a miscellaneous type; and that the other nonmelanocytic disorders, such as verruca vulgaris and black heel, are easily differentiated by their surface profile. More important, the histological examination showed that atypical nevi, malignant melanoma in situ, and acral lentiginous melanoma are exclusively compartmentalized in the miscellaneous type of surface profile. Our data suggested that epiluminescence microscopy may be a useful method for discrimination of plantar benign and malignant melanocytic lesions.