Melanoma

Definition

Melanoma is the most dangerous type of skin cancer. It is also the rarest. It is the leading cause of death from skin disease.

Other common types of skin cancer are squamous cell carcinoma and basal cell carcinoma.

Alternative Names

Skin cancer - melanoma; Malignant melanoma; Lentigo maligna melanoma; Melanoma in situ; Superficial spreading melanoma; Nodular melanoma; Acral lentiginous melanoma

Causes

Melanoma is caused by changes (mutations) in skin cells called melanocytes. These cells make a skin color pigment called melanin. Melanin is responsible for skin and hair color.

Melanoma can appear on normal skin. Sometimes it can develop from moles. Moles that are present at birth may develop into melanomas. Larger moles that are present at birth may be at higher risk for developing melanoma.

There are four major types of melanoma:

The risk for developing melanoma increases with age. However, more and more young people are developing it.

You are more likely to develop melanoma if you:

Other risk factors include:

Symptoms

A mole, sore, lump, or growth on the skin can be a sign of melanoma or other skin cancer. A sore or growth that bleeds, or changes in color can also be a sign of skin cancer.

The ABCDE system can help you remember possible symptoms of melanoma:

Another way to look for possible melanoma is the "ugly duckling sign." This means the melanoma does not look like any of the other spots on the body. It stands out like the ugly duckling in the children's story.


Exams and Tests

Your health care provider will check your skin and look at the size, shape, color, and texture of any suspicious areas with a dermatoscope.

If your provider thinks you might have skin cancer, a piece of skin from the growth will be removed. This is called a skin biopsy. The sample is sent to a lab for examination under a microscope.

A sentinel lymph node (SLN) biopsy may be done in some people with melanoma to see if the cancer has spread to nearby lymph nodes.

Once melanoma has been diagnosed, CT scans or other types of x-rays may be done to see if the cancer has spread.

Treatment

Surgery is almost always needed to treat melanoma. The skin cancer and some surrounding area will be removed. How much skin is removed depends on how deep the melanoma has grown.

If the cancer has spread to nearby lymph nodes, these lymph nodes may also be removed. After surgery, depending on the risk of the disease returning, you may receive chemotherapy or immunotherapy.

Treatment is more difficult when the melanoma has spread to other organs. Treatment involves shrinking the skin cancer and treating the cancer in other areas of the body. You may receive:

If you have melanoma that is hard to treat, you might consider enrolling in a clinical trial. Ask your doctor for more information. Researchers continue to study new treatments.

Support Groups

Sharing with others who have common experiences and problems can help you not feel alone. More information and support for people with melanoma and their families can be found at:

Outlook (Prognosis)

How well you do depends on many things, including how soon the cancer was diagnosed, and how far it has spread.

In its early stage, most melanomas can be cured.

Melanoma that is very deep or has spread to the lymph nodes is more likely to return after treatment. If it is deeper than 4 mm or has spread to the lymph nodes, the cancer is more likely to have spread to other tissues and organs.

If you have had melanoma and recovered, it is very important to examine your body regularly for any unusual changes. Your risk for melanoma increases once you have had this cancer. Melanoma can return years later.

Possible Complications

Melanoma can spread to other parts of the body.

Melanoma treatment can cause side effects, including pain, nausea, and fatigue.

When to Contact a Medical Professional

Contact your provider if you notice a new growth or any other changes in your skin. Also talk to your provider if an existing spot:

Prevention

Some people should see a skin doctor for regular skin exams. These include people with:

A skin doctor can examine you and tell you whether you need regular skin checks. Sometimes, unusual moles are removed to prevent them from turning into melanoma.

You should also examine your own skin once a month. Use a mirror to check hard-to-see places. Use the ABCDE system and the "ugly duckling" sign when checking your skin. 

The best way to prevent skin cancer is to reduce your exposure to sunlight. Ultraviolet light is most intense between 10 a.m. and 4 p.m. Try to avoid sun exposure during these hours. Protect your skin by wearing a hat, long-sleeved shirt, long skirt, or pants when you have to be outside. The following tips can also help:

Other important facts to help you avoid too much sun exposure:

Even though melanoma can develop in some moles, doctors feel that there is no advantage to remove moles to prevent melanoma.

References

Garbe C, Bauer J. Melanoma. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 113.

National Cancer Institute website. Melanoma treatment (PDQ) health professional version. www.cancer.gov/types/skin/hp/melanoma-treatment-pdq. Updated May 27, 2022. Accessed May 30, 2022.

National Comprehensive Cancer Network website. NCCN clinical practice guidelines in oncology: melanoma: cutaneous version 3. 2022. www.nccn.org/professionals/physician_gls/pdf/cutaneous_melanoma.pdf. Updated April 11, 2022. Accessed May 30, 2022.

North JP, Bastian BC, Lazar AJ. Melanoma. In: Calonje E, Bren T, Lazar AJ, Billings SD, eds. McKee's Pathology of the Skin. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 26.


Review Date: 2/18/2022
Reviewed By: Ramin Fathi, MD, FAAD, Director, Phoenix Surgical Dermatology Group, Phoenix, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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