Melanomas and Mechanical Stress Points on the Plantar Surface of the Foot

To the Editor: Sun exposure is widely recognized as the main causative factor in cutaneous melanoma. However, melanomas also emerge in areas of the skin (such as palmoplantar surfaces) that are not exposed to the sun. Genetic analyses indicate that melanomas in sun-exposed skin are frequently associated with oncogenic BRAF mutations that are largely absent from palmoplantar lesions.1 These findings suggest that different pathogenic processes may be at work.2 Here we report on a series of patients with melanomas that developed in areas of plantar surfaces that had the most mechanical stress. We retrospectively collected data on 123 patients (54 . . .