Acral lentiginous melanoma

This page was reviewed under our medical and editorial policy by

Frederick L. Durden, Jr, MD, Plastic and Reconstructive Surgeon & Microsurgical Reconstructive Surgeon

This page was reviewed on February 24, 2023.

Acral lentiginous melanoma (ALM) is a rare form of skin cancer that typically appears on the palms and soles, as well as under the nail beds. Despite its relative rarity, acral lentiginous melanoma is the most commonly diagnosed type of melanoma seen in darker-skinned individuals. It tends to be diagnosed between the ages of 60 and 70.

Common sites for acral lentiginous melanoma

This form of melanoma tends to show up on:

  • Toenails
  • Fingernails
  • Toes (especially the big toe)
  • Feet
  • Hands
  • Heels

Causes and risk factors

Unlike skin cancers that are caused by exposure to the sun’s ultraviolet (UV) light, acral lentiginous melanoma is not known to be caused by the sun’s harmful rays. These cancers develop on parts of the body that aren’t regularly exposed to sun. Researchers don’t know exactly what causes acral lentiginous melanoma, but it’s believed to be linked to pressure, friction, irritation and trauma to the area.

What does acral lentiginous melanoma look like?

As a general rule, acral lentiginous melanoma is a flat gray, brown or black lesion with irregular borders. Another variant that forms as a reddish, pinkish or orangish lesion is called amelanotic melanoma. When these cancers aren’t caught early, they may become inflamed and itchy.

Acral lentiginous melanoma symptoms

Acral lentiginous melanoma symptoms may include:

  • Unexplained streak in a nail
  • Changing spot in or connected to a mole on the foot or hand
  • Black, gray, tan or brown mark with irregular borders
  • Reddish, pinkish or orangish lesion with irregular borders
  • Changing or growing lesion on the foot or hand
  • Thick patch of skin on the sole or palm
  • Itchy or inflamed lesion on the hands or feet

Acral lentiginous melanoma treatment

Acral lentiginous melanoma is typically treated with surgery. The goal is to remove the lesion as well as some healthy surrounding skin to capture as much of the cancerous margins possible. The surgeon may also remove surrounding lymph nodes to determine whether the cancer has begun to spread.

Some patients may require further treatment with newer immunotherapy agents and targeted cancer drugs as well.


Though the five-year melanoma-specific survival rate for acral lentiginous melanoma is lower than it is for other forms of melanoma, the majority of patients survive at least five years. Survival rates in individuals with darker skin tend to be lower. Some research suggests the reason may be that those with darker skin may not notice the early pigmentation changes and tend to seek treatment when the cancer is more advanced. Other research suggests misdiagnosis may contribute to lower survival rates because of the misconception that risks for melanoma are lower for people of color and only skin exposed to the sun is at risk.

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