Acral lentiginous melanoma

Acral lentiginous melanoma is uncommon (5% of melanomas among white people) (1).

• although it is uncommon in all ethnic groups, in Asians, Hispanics and in patients of African descent it is the most common type of melanoma
• it is thought have no association with UV exposure (2)

It is seen on the soles (often involves the heels) and less often, the palms. It has a raised dark area surrounded by a paler macular - lentiginous - area often extending for several centimetres around the elevation.

Periungual melanoma may be regarded as a variant of acra-lentiginous melanoma. Its clinical importance is that it is often misdiagnosed. Brown pigmentation on the nail fold is suggestive of melanoma - Hutchinson's sign. Periungual warts or plantar warts are uncommon in patients over 40 years of age.

Reference:

• (1) Markovic SN et al. Malignant melanoma in the 21st century, part 1: epidemiology, risk factors, screening, prevention, and diagnosis. Mayo Clin Proc. 2007;82(3):364-80
• (2) Bishop JN et al. The prevention, diagnosis, referral and management of melanoma of the skin: concise guidelines. Clin Med. 2007;7(3):283-90