Definition

Melanoma is a type of skin cancer. It is the least common form of skin cancer, but it can be more serious because it is more likely to spread to other parts of the body.

Melanoma arises from the type of cell called melanocytes that give moles their dark colors. These cells can be found in the skin, eyes, digestive system, nail beds, or lymph nodes. Although melanoma is most common in the skin, it may also arise in these other areas.

Treatment for melanoma depends on how early it is detected, or if the melanoma has spread.

Causes

Cancer occurs when cells in the body divide without control or order. Eventually these uncontrolled cells form a growth or tumor. The term cancer refers to malignant growths. These growths invade nearby tissues and spread to other parts of the body. It is not clear exactly what causes these problems in the cells but is probably a combination of genetics and environment.

Risk Factors

The most common risk factor for melanoma is exposure to ultraviolet radiation. The most common source of this radiation comes form the sun, but it is also found in sun lamps and tanning booths.

Melanoma is found most often in older adults, but it can happen in young adults. It is more common in people who are Caucasian. Other factors that may increase your risk of developing melanoma include:

• Certain types of moles called dysplastic nevi, or atypical moles
• Large nevi present at birth
• Fair skin, freckling
• Red or blonde hair
• Light-colored eyes
• Family members with melanoma
• Excessive skin exposure to the sun without protective clothing or sunscreen
• Certain occupations, such as telephone repair employees, harbor masters, and electrical fitters
• Suppressed immune system

Symptoms

Melanomas are not usually painful. They often have no symptoms at first.

The first sign is often a change in the size, shape, color, or feel of an existing mole. Melanoma may also appear as a new, dark, discolored, or abnormal mole. Remember that most people have moles. Almost all moles are benign.

The following are signs that a mole may be a melanoma (ABCDE criteria):

• Assymetry or uneven shape—one half does not match the shape of the other half
• Border or edges that are uneven—ragged, notched, blurred, or irregular; pigment may spread into surrounding skin
• Color variation or uneven color—color is uneven with shades of black, brown, or tan, and possibly even white, gray, pink, red, or blue
• Diameter or size—usually larger than the eraser of a pencil (6 millimeters or ¼ inch)
• Evolution or change—usually growing larger, changing shape, changing color, or changing texture

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor will look at your skin and moles. You may be referred to an eye specialist if melanoma of the eye is suspected. A skin biopsy of the suspicious area will be done. The tissue will be examined under a microscope.

Your doctor may also examine lymph nodes. Enlarged lymph nodes may suggest the spread of melanoma. A sample of lymph node tissue may also be removed for testing.

Once melanoma is found, more tests will be done to determine the stage of cancer. Melanoma is staged like other cancers, from I to IV. The stage will help determine your treatment course.

Treatment

Treatment will depend on the location and stage of the melanoma. Talk to your doctor about the best treatment plan for you. Treatment options may include one or more of the following:

Prevention

To help reduce your chance of developing melanoma:

• Avoid spending too much time in the sun
• Protect your skin from the sun:
  • Wear a long-sleeved shirt and long pants, a wide-brim hat, and sunglasses
  • Use sunscreens with a sun protection factor (SPF) of at least 30
  • Avoid exposure during the peak hours of the day
• Avoid sun lamps and tanning booths

Early diagnosis and treatment is important. Take the following steps to find melanoma in its early stages:

• See your doctor if you think you have notice any changes in any moles on your skin.
• If you have many moles or a family history of melanoma, have your skin checked regularly for changes in moles.
• Ask your doctor to show you how to do a skin self-exam. Do self-exams to look for any new or changing moles.

Skin Cancer Foundation http://www.skincancer.org

Canadian Dermatology Association http://www.dermatology.ca

Melanoma treatment—for health professionals (PDQ). National Cancer Institute website. Available at:
http://www.cancer.gov/types/skin/hp/melanoma-treatment-pdq#section/_1
Updated July 14, 2015. Accessed August 5, 2015.

Melanoma skin cancer. American Cancer Society website. Available at:
http://www.cancer.org/acs/groups/cid/documents/webcontent/003120-pdf.pdf
Accessed August 5, 2015.

Physician quality reporting system quality measures. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated August 19, 2014. Accessed August 5, 2015.

5/18/2015 DynaMed’s Systematic Literature Surveillance
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Perez-Gomez B, Pollán M, Gustavsson P, et al. Cutaneous melanoma: hints from occupational risks by anatomic site in Swedish men. Occup Environ Med. 2004;61(2):117-126.