Lentigo Maligna Developing in Meleda-type Palmoplantar Keratosis

Abstract

A 54-year-old housewife with a history of slowly enlarging palmoplantar keratosis of over 40 years’ duration developed an asymptomatic, round, irregularly pigmented macule of about 1.5cm in diameter in the right sole at the age of 44 years following a mild trauma. The pigmented macule slowly enlarged. The lesion was totally excised together with a full-thickness skin graft. Histologically, abundant melanin granules, vacuolated cells and abnormal, large melanocytes were found in the basal cell layer of the pigmented macule. Electron-microscopically, the melanosomes were increased.