(Malignant Melanoma; Cutaneous Melanoma)
Melanoma is a skin cancer of the melanocytes, the cells that produce skin color and give moles their dark color. Under normal conditions, moles are benign skin tumors. Sometimes, however, a mole can develop into melanoma. A new mole may also be an early melanoma.
Melanoma skin cancers are less common than carcinoma skin cancers. But melanomas are more dangerous because they are far more likely to spread to other parts of the body.
Cancer occurs when cells in the body (in this case skin cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and can spread to other parts of the body. A benign tumor is unable to invade or spread.
For information about carcinoma skin cancers, see the fact sheet on basal and squamous cell carcinomas.
Ultraviolet radiation from the sun is the main cause of skin cancer. But artificial radiation from sun lamps and tanning booths can also cause skin cancer.
A risk factor is something that increases your chance of getting a disease or condition.
- Certain types of moles called dysplastic nevi, or atypical moles. These types of moles look somewhat like melanoma. (See symptoms section for description of melanoma moles.)
- Large nevi present at birth
- Age: Peak incidence in early adulthood and again later in life
- Fair skin
- Red or blonde hair
- Light-colored eyes
- Family members with melanoma
- Excessive skin exposure to the sun without protective clothing or sunscreen
- Suppression of the immune system, caused either by disease or treatment
Melanomas are not usually painful. The first sign of melanoma is often a change in the size, shape, color, or feel of an existing mole. Melanomas also may appear as a new, black, discolored or abnormal mole. It's important to remember that most people have moles, and almost all moles are benign.
The following are signs that a mole may be a melanoma:
Uneven Shape -The shape of one half does match the shape of the other half.
Ragged Edges - The edges are ragged, notched, blurred, or irregular and the pigment may spread into surrounding skin.
Uneven Color - The color is uneven with shades of black, brown or tan, and possibly even white, gray, pink, red or blue.
Change in Size - The mole changes in size, usually growing larger. Melanomas are usually larger than the eraser of a pencil (5 mm or 1/4 inch).
Change in Texture - The mole may begin to have fine scales. In more advanced cases, a mole may become hard or lumpy.
Itching - The mole may start to itch, or in more advanced cases it may ooze or bleed.
The doctor will ask about your symptoms and medical history, and perform a physical exam. The doctor will examine your skin and moles. He or she will take a biopsy (tissue sample) of any suspicious moles and send them to a laboratory for testing. Other moles will be watched over time.
The doctor may also examine lymph nodes in the groin, underarm, neck, or areas near the suspicious mole. Enlarged lymph nodes may suggest the spread of a melanoma. The doctor may need to remove a sample of lymph node tissue to test for cancer cells.
Once melanoma is found, tests are performed to find out if the cancer has spread and, if so, to what extent. Treatment for melanoma depends on whether the cancer has spread.
Surgery – removal of the melanoma and some healthy tissue surrounding it. If a large area of tissue is removed, a skin graft may be done at the same time. For this procedure, the skin that was removed is replaced with skin from another part of the body. Lymph nodes near the tumor may be removed during surgery because cancer can spread through the lymphatic system.
Chemotherapy – uses drugs to kill cancer cells. Chemotherapy may be given in many forms including: pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body killing mostly cancer cells, but also some healthy cells.
Biological Therapy – medications or substances made by the body to increase or restore the body's natural defenses against cancer. Also called biological response modifier (BRM) therapy. Examples include interferon, interleukin 2 and melanoma vaccines.
Radiation Therapy (Radiotherapy) – The use of radiation to kill cancer cells and shrink tumors. This is not a cure for melanoma and is used only in combination with other therapies.
To reduce your chance of getting melanoma:
- Avoid spending too much time in the sun.
- Protect your skin from the sun with clothing, including a shirt, sunglasses, and a hat with a broad brim.
- Use sunscreens with a sun protection factor (SPF) of 15 or more on skin that will be exposed to the sun.
- Avoid exposing your skin to the sun between 10:00 a.m. and 2:00 p.m. standard time, or 11:00 a.m. and 3:00 p.m. daylight savings time.
- Don't use sun lamps or tanning booths.
Take the following precautions to find melanoma in its early stages:
- If you have a mole that looks similar to the ones described above, have your skin examined by a doctor.
- 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.