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melanoma

Amelanotic Melanoma: Symptoms, Causes, Treatment

melanomaA patient recently came to the office concerned about a new dark mole on her leg. During her full body skin examination, I noticed a pink bump on her back.  I asked her about it and she said it was a bug bite that was taking a long time to heal.  Because of the appearance of the lesion when I examined it with a dermatoscope, I recommended a biopsy. Unfortunately, the pink spot on her back turned out to be a melanoma. The mole on her leg was benign.

 

Most patients are concerned when they spot a new dark mole, but it’s not widely recognized that melanoma can present as a pink or colorless skin lesion. Amelanotic melanoma is a serious form of skin cancer where the cells do not make melanin or pigment. It is responsible for approximately 2-20% of melanoma cases1. Because of their lack of color, diagnosis of this type of melanoma may be delayed until it reaches an advanced stage.

Symptoms

One of the most obvious symptoms of amelanotic melanoma is the sudden appearance of a red, pink, or skin-colored spot on your body where it wasn’t before. Melanomas also grow and may change shape, becoming a larger bump over time. Amelanotic melanoma may not present with the classic ABCD criteria (Asymmetry, Border Irregularity, Color variation, and Large Diameter) that are typically associated with melanoma warning signs. Expanding the ABCD warning signs to include the 3 Rs (Red, Raised, Recent change) may help in the early detection of amelanotic melanoma2. It is also estimated that about 25% of melanomas of the nail are amelanotic, so checking your nails should be a regular part of self-skin examinations. It is important to note that melanoma may present differently in individuals of color, therefore regular self-skin examinations are essential in the early detection of these skin cancers.

Causes

Melanoma occurs when the DNA in your skin cells becomes damaged, which can cause the cells to grow out of control and become cancerous. Exposure to the sun for long periods of time can damage your skin cells and increase your risk for melanoma. This risk is increased in patients with fairer skin, individuals of European descent, those with many moles (especially 50 or more), a family history of melanoma, and patients with a weakened immune system from an existing condition3. The use of tanning beds has also been associated with an increased risk for melanoma and should be avoided4.

Treatment

The most common treatment for melanoma is surgical removal.  However, melanoma can spread to the lymph nodes, necessitating the removal of one or more nodes. Advanced melanoma may need to be treated with chemotherapy and/or radiation. Biological therapy (or drugs that aid your immune system in killing cancer cells) as well as targeted therapy (medications that weaken cancer cells) are other common melanoma therapies. Patients with a history of a previous melanoma are 4 times more likely than the general population to develop a subsequent invasive melanoma, therefore full body skin examinations should be performed by a dermatologist every 3 months after a melanoma diagnosis.

 

References:
1.         Thomas, N.E., Kricker, A., & Waxweiler, W. Comparison of Clinicopathologic Features and Survival of Histopathologically Amelanotic and Pigmented Melanomas: A Population-Based Study. JAMA Dermatol. 2014;150(12):1306-1314. doi:10.1001/jamadermatol.2014.1348
2.         Kim, S.J., Park, H.J., Lee, J.Y., Cho, B.K., A Case of Subungual Melanoma. Ann Dermatol. 2008 Mar; 20(1): 26–28. Published online 2008 Mar 31. doi:  10.5021/ad.2008.20.1.26
3.         American Cancer Society. Risk Factors for Melanoma Skin Cancer. Available online at: https://www.cancer.org/cancer/melanoma-skin-cancer/causes-risks-prevention/risk-factors.html
4.         American Academy of Dermatology. Indoor Tanning. Available online at: https://www.aad.org/media/stats/prevention-and-care