Acral lentiginous melanoma - Nail and Distal Digit
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Synopsis
ALM occurs in all races and ethnicities with a similar incidence; however, it is disproportionately represented compared with other melanoma subtypes among individuals with darker skin colors, including those of African, Hispanic, and Asian descent. In these individuals, the diagnosis is often delayed, and therefore the prognosis is worse than in individuals with lighter skin colors.
Because ALM typically occurs in minimally sun-exposed areas in patients of all phototypes, it has been suggested that sun exposure is less of a risk factor than in the other subtypes of melanoma, indicating other possible etiologies. This has led to the theory that trauma may be a risk factor leading to the development of ALM, and some studies have shown an association with injuries to the foot. Also, ALM occurs more frequently at physically stressed and weight-bearing sites of the volar region and nail apparatus. A pattern of spread has been observed with the long axis along natural creases on the sole. Genomic studies have also revealed different mutational profiles compared with other melanoma subtypes and identified KIT mutations in a subset of acral melanomas.
Codes
ICD10CM:C43.9 – Malignant melanoma of skin, unspecified
SNOMEDCT:
254732008 – Acral lentiginous malignant melanoma of skin
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Last Reviewed:11/07/2021
Last Updated:11/07/2021
Last Updated:11/07/2021
Patient Information for Acral lentiginous melanoma - Nail and Distal Digit
Overview
Acral lentiginous melanoma (ALM) is a type of melanoma skin cancer that occurs on the hands and feet. Acral refers to your limbs or extremities and lentigines are dark-colored (pigmented) spots.In ALM, pigmented cells may form a tumor that looks like a brown or black spot or patch. Sometimes, but not usually, ALM is amelanotic, which means the growing cells are skin-colored or pink.
Who’s At Risk
Both men and women of all races and ethnicities are at risk for melanoma. ALM is the most common type of melanoma in people with dark skin and in people of East Asian descent.ALM is more common in adults over 50 years of age. People with a family history of melanoma have a higher risk.
Sites where the foot has been previously injured are more likely to develop ALM.
Signs & Symptoms
This form of melanoma often resembles a black, brown, or blue patch or bump. It can be mistaken for a wart. It is usually seen on the foot, but it may be on your hand instead. The tumor can be flat or raised, and it usually has color variation and crooked borders.Because ALM is sometimes amelanotic, it is possible for the patch or bump to be pink or skin-colored. Ask your health care provider about any unusual growths on your hands or feet, especially if you have a personal or family history of skin cancer.
Self-Care Guidelines
ALM must be treated by a health care professional. It is easier to treat when it is found early. Do a regular self-examination of your skin. Watch darker or lighter patches and moles for changes.When to Seek Medical Care
Show your doctor all growths or patches under your fingernails and toenails and on your palms and soles.If you have a parent, sibling, or child with skin cancer, or if you have a personal history of skin cancer, talk to your doctor about being screened for melanoma regularly.
Treatments
The most common treatment is to remove the melanoma.More advanced ALM can be treated with chemotherapy or immunotherapy medications.
Acral lentiginous melanoma - Nail and Distal Digit
See also in: Overview