A case of malignant melanoma arising on the hyperkeratotic little finger of
a 46-year-old patient with palmoplantar keratoderma is reported. A pigment
ed lesion had been present since childhood, over a period of two years it b
ecame larger and darker and had occasion ally bled over the past two months
. Histopathologic investigation revealed hyperkeratosis, hypergranulosis, a
nd acanthosis on the left palm and malignant melanoma on the macule of the
left little finger.