Causes of Acral Melanoma

Acral melanoma (ALM) is a rare, aggressive form of skin cancer that affects the pigment in human skin. It is most commonly found on the palms, soles, and nail beds.

The underlying cause of ALM is poorly understood, but one thing is clear: Unlike other forms of skin cancer, it has nothing to do with sun exposure. This means that people with darker skin are generally less likely to develop most types of skin cancer, and they have the same risk of developing ALM as people with lighter skin pigmentation.

This article will review the potential causes of ALM and the risks you need to know about.

Common causes

Acral melanoma (ALM) is a subtype skin Melanoma.This means that this skin cancer occurs in melanocytes– cells responsible for making the pigments that determine skin color (melanin) – grows out of control and forms tumors.

The exact cause of ALM is unclear. Unlike most skin cancers, ALM is not associated with sun exposure.

Melanin provides some protection from ultraviolet (UV) radiation, so people with darker skin are generally at a slightly lower risk of skin cancer than people with lighter skin. But because ALM is not associated with UV exposure, darker-skinned people are just as likely to develop this type of cancer as lighter-skinned people.

ALM and dark skinned people

ALM is a rare skin cancer that accounts for 2%–3% of all melanoma cases. However, it is traditionally the most common type of malignant melanoma in people with dark skin, especially African Americans, and people of Asian and Middle Eastern ancestry.

Although sun exposure and other lifestyle factors, such as smoking, are not associated with ALM, researchers have identified a number of other factors that may increase the risk of developing ALM. These include:

  • Previous hand or foot trauma (or minimally invasive, injury from repetitive stress on tissue)
  • exposure to certain agricultural chemicals
  • systemic inflammation

However, there is insufficient evidence to suggest a causal relationship between ALM and any of the above factors.


Like most skin cancers, ALM is thought to be caused by genetic mutations (changes) in melanocytes, which prompt these cells to grow out of control.

Certain genes (called tumor suppressor genes) are tasked with repairing errors in DNA, which help control cell growth. However, genetic mutations can cause tumor suppressor genes to be turned off. This can lead to uncontrolled cell growth and can lead to cancers such as ALM.

ALM has been shown to be caused by mutations in the KIT, BRAF, NRAS and NF1 genes. Specifically, mutations in the KIT gene were found in more than one-third of acral melanoma cases.

In addition, one study found mutations in the cyclin D1 gene in 45 percent of ALM cases, but more research is needed to reveal the role of these genes in the cause and spread of this deadly disease.

Genetic mutations can be acquired or inherited. In most cases, the genetic mutation associated with ALM occurs during a person’s lifetime and is not inherited from their parents.

But there may be a genetic component involved in the development of this melanoma. A study found that people with ALM were more likely to have another cancer or a family history of cancer other than melanoma.

Lifestyle Risk Factors

While lifestyle factors such as smoking, diet, and exercise are not associated with increased ALM risk, it is important to note that maintaining a healthy weight, not smoking, exercising, and eating a healthy diet will always limit cancer risk.


The exact cause of ALM remains a mystery. Certain genetic mutations, inflammation, and trauma to the hands and feet may put you at a higher risk of developing ALM, but more research is needed to find causal factors that put you at higher risk for this potentially deadly disease.

VigorTip words

There is a misconception that melanoma only occurs in sun-exposed areas of the skin, and dark-skinned people are not at risk for melanoma. Therefore, some people may overlook skin changes, delaying the diagnosis of ALM. This can lead to ALM being discovered at a later stage that is more difficult to handle.

Knowing the signs and symptoms of ALM is essential for early diagnosis and treatment. If you notice irregular black, gray, tan, or brown markings on your body, especially on the palms and soles of your feet, contact a healthcare professional for an examination.