The Prevalence of Melanocytic Nevi on the Soles in the Japanese Population.

Background: Acral lentiginous melanoma (ALM) is the most common type of melanoma in Japan. The association between ALM and acral nevus has not been elucidated.Objective. To investigate the prevalence and dermatoscopic patterns of plantar melanocytic nevi on the soles in the Japanese and to evaluate the relationship between acral nevi and ALM.Methods: All outpatients (N = 1697) and melanoma patients (N = 104) were included. We examined the number, size, and dermatoscopic images of nevi.Results: In the control group, the prevalence of plantar nevi was 10.9%, and the mean size was 3.8 +/- 2.4 mm. The prevalence of nevi in patients with ALM and melanoma in situ on the soles was 8.6% and that of patients with melanoma on other sites was 14.5%. The main dermatoscopic pattern was "parallel furrow" in both groups.Limitations: This was a clinical observational study only.Conclusion: The number, size, and dermatoscopic patterns of nevi on the soles of patients with ALM and melanoma in situ on the soles did not differ from those of the control group. (J Am Acad Dermatol 2009;60:767-71.)