RESUMO
BACKGROUND: Olmsted syndrome is a rare congenital disorder with mutilating palmoplantar keratoderma, periorificial keratotic plaques, and other variable features. OBJECTIVE: We describe a 65-year-old woman with Olmsted syndrome complicated by the occurrence of a malignant melanoma inside the plantar keratoderma. To our knowledge, this is the first reported case of such an occurrence in Olmsted syndrome. The published cases of this rare disorder are reviewed. CONCLUSION: An association between malignant epithelial tumors and Olmsted syndrome has already been reported. The association of malignant melanoma with other types of palmoplantar keratodermas has been reported. This may suggest a predisposition to melanocytic as well as squamous cell malignancies in congenital keratodermas. Oral retinoids appear to be the most promising treatment for Olmsted syndrome and for other symptomatic keratodermas.