What is Amelanotic Melanoma?

Amelanotic melanoma accounts for 2-20% of all melanomas. Although comparatively rare, it is an aggressive type of melanoma skin cancer characterized by the absence of melanin pigment. Melanin gives a primary melanoma its dark color, one of the most easily recognized melanoma warning signs.

Because amelanotic melanomas do not look like other melanomas, they are harder to diagnose and treat, with potentially lethal consequences.

Please continue reading to learn more about these skin cancers, including the risk factors for developing amelanotic melanoma, their appearance, diagnosis, treatment options, and survival rates.

What does an amelanotic melanoma look like?

Amelanotic melanomas lack melanin pigment. Therefore, they commonly present as skin-colored, pink, or red skin lesions with brown or gray edges. The other most apparent symptoms of an amelanotic melanoma are similar to a pigmented melanoma. Amelanotic melanoma symptoms may include:

The sudden appearance of a skin growth or a skin growth that changes in size, shape, color, or texture (anything larger than the size of a pencil eraser or with an irregular border is concerning)
A painful, bleeding, itching, oozing or crusted over mole, sore, or spot.
An open sore that has not healed for more than three weeks.

Remember that amelanotic melanomas don’t contain melanin and are harder to see. For this reason, you should pay close attention to all skin lesions, including those with little to no pigmentation.

What can be mistaken for amelanotic melanoma?

Amelanotic melanomas are easily confused with basal cell carcinomas and squamous cell carcinomas. They can also be mistaken for harmless moles or scars. This is dangerous because amelanotic melanomas can spread faster than some of the more easily recognized melanomas.

Note: In contrast to amelanotic melanomas, nodular melanomas are a type of skin cancer in which the melanin-producing skin cells grow uncontrolled and form tumors. Nodular melanoma accounts for around 15% of all melanomas and grows faster than other types of cancer.

Are amelanotic melanoma serious?

Yes, an amelanotic melanoma is serious for two reasons. One, survival rates after diagnosis with amelanotic melanoma are less compared to pigmented melanoma. This is because an amelanotic melanoma is usually a more advanced melanoma at the time of diagnosis.

Two, there is some evidence that an amelanotic melanoma grows faster than a common melanoma. That’s why early detection and treatment of amelanotic melanoma is necessary.

How does amelanotic melanoma start?

The causes of amelanotic melanomas are the same as the causes of more easily recognized pigmented melanomas. Mutations in the DNA of skin cells cause them to grow out of control and become cancerous (melanoma). These mutations are most commonly caused by exposure to UV rays in sunlight and tanning beds.

Some mutations can be inherited. For example, people with a condition called xeroderma pigmentosum (XP) are unable to repair DNA damage caused by UV exposure and are therefore at greater risk of developing melanoma.

What are the risk factors for amelanotic melanoma?

The risk factors for amelanotic melanoma are the same as the risk factors for all skin cancers and include:

Excessive exposure to ultraviolet rays in sunlight and tanning beds.
Having more than 50 moles on the body.
Having fair skin, blond or red hair, and light eyes.
Being White (melanoma is 20-30 times more common in Caucasian people than African Americans).
Having a family or personal history of skin cancers.
Having a weak immune system.
Having xeroderma pigmentosum (XP).

How is amelanotic melanoma diagnosed?

Amelanotic melanomas can pose a diagnostic challenge because they lack pigment. Doctors can confirm a diagnosis by obtaining a skin biopsy (small skin sample) and examining it under the microscope for evidence of cancerous cells. Besides cancer cells, doctors also look for other characteristic features such as thickness, ulceration, mitotic rate (the rate at which cells divide), and the presence of tumor-infiltrating lymphocytes (immune system cells).

Other tests your doctor may order include ultrasound images of lymph nodes, CT scans, and MRI scans to determine the exact size of the tumor, PET scans, and sentinel lymph node biopsy.

What is the treatment for amelanotic melanoma?

Treatment for all melanomas, including amelanotic melanomas, depends on the stage of the skin cancer. Common treatments include surgery to remove the amelanotic melanoma cells and/or radiation therapy and chemotherapy to kill cancer cells. Other treatments include immunotherapy, biological therapy, and targeted therapy to boost the body’s immune system, weaken cancer cells, and prevent cancerous tumor growth.

What is the survival rate for people with amelanotic melanoma?

For melanoma overall, the 5-year survival rate is 93 percent. However, the survival rate for amelanotic melanoma may be slightly lower (88 percent). This is mainly due to amelanotic melanomas presenting as non-pigmented lesions that are harder to notice and can be confused with other skin problems. As a result of these difficulties with diagnosing amelanotic melanomas, they are often discovered at advanced stages.

Last Word…

Getting a pathology report with a diagnosis of skin cancer can be overwhelming and worrisome. However, while an aggressive type of melanoma, amelanotic melanomas have a good outlook if they are discovered in the early stages. Nonetheless, because these skin cancers lack pigment, they are more likely to go unnoticed.

You should learn the ABCD warning signs of melanomas and keep an eye on any existing moles. It’s recommended to perform monthly self-skin exams and see a dermatologist for annual skin cancer screenings. It’s recommended to go more often if you have a history or family history of skin cancer or are at increased risk due to a weakened immune system.

Avoiding excessive sun exposure and the use of a tanning bed is your best protection against all types of skin cancers.

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