How to Diagnose Acral Melanoma

Acral melanoma (ALM), also abbreviated as Acral melanomais an aggressive subtype of cutaneous melanoma (skin cancer) that occurs on the hands and feet.

The word “acral” is derived from the Greek word for the highest or highest part of the limbs. The term “lentiginous” refers to the initial origin of these tumors as macular (flat) brown spots that resemble benign freckleor liver spots.

Early detection of ALM is highly curable, underscoring the importance of early diagnosis and treatment.

ALM is usually diagnosed by biopsy, in which a sample of tissue is removed for examination in a laboratory. ALM looks similar to other types of skin cancer, so it is skin pathologist (Doctors who specialize in diagnosing diseases by looking at samples of skin, hair, and nails) need to make an accurate diagnosis.

This article will review how to diagnose ALM.


The earliest signs of acral melanoma (ALM) are oddly shaped, discolored patches of skin surrounded by normal skin. The skin may be raised and discolored in black, gray, tan, red, or brown with irregular edges. Occasionally, brown or tan streaks may appear under the nails of the hands or feet, especially the big toe or thumb.

ABCDE Rules for Self-Testing

Using the “ABCDE” rule can help describe these ominous looking moles: “A” for asymmetrical; “B” for irregular border; “C” for color change; “D” for diameter, large; “E” for constant The nature of evolution or growth.

If you notice one or more of these signs, you will need to be examined by a health care professional, such as your primary care doctor or dermatologist.

ALM is extremely rare, but seek immediate medical attention if you notice one or more of the following skin changes:

  • Ulceration or bleeding when you see new oddly shaped or discolored patches of skin
  • discolored patches of skin that have grown
  • Skin irregularities larger than 6 mm
  • Skin patches that have formed irregular borders

How to recognize early signs of skin cancer

physical examination

After sharing your signs and symptoms, a health care professional will perform a physical examination, examining all the skin on your body. Get a full body skin exam if you have:

  • Suspected mole or skin lesion
  • Symptoms of early skin cancer
  • Past history of skin cancer
  • 50 or more moles
  • Atypical moles, also known as dysplastic mole
  • Family history of skin cancer.

During the exam, the healthcare provider will look for suspicious growths, moles, or lesions on the skin, including examining the scalp by parting the hair. They usually use bright light and sometimes a magnifying glass for a more thorough examination.

In addition to using the ABCDE rules to identify the ominous features of moles, your healthcare provider may point out other signs of melanoma, including:

  • Elevation, such as thickening or elevation of a previously flat mole
  • Scaling, erosion, oozing, bleeding or crusting on the skin surface
  • Redness, swelling, or the appearance of new small patches around larger lesions of the surrounding skin (called satellite pigmentation)
  • Itching, tingling, or burning sensation when touched
  • Fragile skin, such as softening or small pieces that fall off easily

In the early stages, it is difficult to distinguish between ALM and benign mole (noncancerous moles), so your healthcare provider or dermatologist may use dermoscopy.

This is a special procedure that can help get an accurate diagnosis. During a dermoscopy, your healthcare provider will use a microscope and an incandescent light to examine the details of the tiny structures of melanocyte skin lesions. Dermoscopy reveals hard-to-see skin changes that are not visible to the naked eye.

What does skin cancer look like?


If ALM is suspected, your healthcare provider will recommend a biopsy, a procedure in which a sample of tissue is removed and sent to a laboratory to be studied under a microscope.

A narrow border excisional biopsy is recommended for the diagnosis of ALM. In this procedure, the entire tumor and a small amount of normal tissue around it (depending on the thickness of the tumor) are surgically removed. A dermatopathologist then examines the tissue under a microscope for signs of malignancy and staging.

Choosing the Right Biopsy for the Type of Skin Cancer

Laboratory and Imaging

Imaging and other laboratory tests, such as blood tests, are not recommended if you have localized ALM that has not spread and you have no other symptoms.

In later stages of the disease, your healthcare provider may order blood tests to measure enzyme levels lactate dehydrogenase (LDH). Elevated levels of LDH can indicate tissue damage and help determine if the cancer has metastasized (spread).

Chest X-rays can also be used to detect lung metastases. However, for cutaneous melanomas such as ALM, imaging techniques tend to have a high rate of false positives (it turns out you have the condition when you don’t).

Differential diagnosis

The differential diagnosis of ALM (the process of distinguishing two or more diseases) is relatively broad. A list of other conditions that can mimic ALM include:

  • other melanocytic tumor (tumor on the skin) eg freckle, congenital acral nevusand Acquired acral nevus
  • Fungal and bacterial infections
  • trauma-related bleeding (Black Claw)
  • scleroderma (black or brown raised areas of skin)
  • chronic wound
  • Wartidae (wart)
  • Other skin cancers that may have secondary hyperpigmentation (transfer of pigment from another cell), such as squamous cell carcinoma or Pore ​​canceror skin melanoma

See pictures to determine if your mold is benign or cancerous


A biopsy of the associated ALM lesion is required to make a diagnosis. Before the biopsy, a healthcare provider will ask about your signs and symptoms and examine the affected area.

VigorTip words

ALM is very rare, so your skin changes are likely the result of another condition. Nonetheless, understanding the signs and symptoms of ALM can lead to early diagnosis and treatment. This is key because early resolution of ALM is a highly curable disease.