[Clinical and histopathologic analyses of pigmented macular lesions on the soles of Japanese--proposal of a clinical guideline for detection of early malignant melanoma on the sole].

Of 92 pigmented macular lesions on the soles of Japanese, 88 lesions were histologically confirmed to be melanocytic: 65 ordinary acquired melanocytic nevi, 9 congenital melanocytic nevi, 5 dysplastic nevi, and 5 possible and 4 definite lesions of early malignant melanomas. None of the ordinary acquired melanocytic nevi were more than 7 mm in maximum diameter. Excluding congenital melanocytic nevi, there were 8 lesions whose greatest diameters were more than 7 mm: 2 dysplastic nevi, and 2 possible and 4 definite lesions of early malignant melanoma. Judging from the data obtained in this study, we propose the following clinical guideline for the detection of early lesions of malignant melanoma on the sole. If the pigmented lesions have no possibility of being congenital melanocytic nevus, black heel, lesions of Peutz-Jeghers syndrome, or 5-FU induced lesions, measure the maximum diameters. 1) Lesions with a diameter of more than 7 mm should be excised for histological evaluation. 2) Lesions with a diameter between 6 and 7 mm should be examined histologically when they show conspicuous irregularity in shape, color and/or border or are observed on the soles of a patient older than 50.