EFFECTIVE DETECTION OF PLANTAR MALIGNANT MELANOMA

Background: As the sole of the foot is the most prevalent site of malignant melanoma in non-Caucasians, early detection of the neoplasm at this anatomical site is very important. In our previous study, we proposed a clinical guideline that acquired melanocytic lesions on the sole larger than 7 mm in maximum diameter should be examined histologically. Methods: Eighty-one Japanese patients with the complaint of plantar pigmented lesions were screened at our dermatology clinic during 3 years using the 7-mm criterion. Results: Of the total 80 melanocytic lesions on the sole, 14 lesions were larger than 7 mm in maximum diameter, excluding congenital lesions. Diagnoses of the 14 “large” lesions were as follows: advanced malignant melanoma, 8 lesions; early malignant melanoma (malignant melanoma in situ), 1 lesion; acquired melanocytic nevus, 4 lesions, and volar melanotic macule, 1 lesion. Conclusions: The present study confirmed the validity of the 7-mm criterion for the early effective detection of plantar malignant melanoma.