Melanoma is a dark-pigmented tumor -- usually cancerous -- that begins in the cells that give the skin its coloring. It is almost always curable in the early stages. However, it is likely to spread, and once it has spread to other parts of the body the chances for a cure are significantly reduced.

What is melanoma?

Melanoma is an aggressive form of skin cancer that can spread to anywhere in the body.

It occurs in the melanocytes, or the cells that color the skin, which are found throughout the lower part of the epidermis, or outer layer of skin.

In men, melanoma is often found on the shoulders, hips, head, and neck. In women, it often develops on the arms and legs.

Melanoma normally occurs in adults, but it is sometimes found in children and adolescents.

The prognosis, or chance of recovery, and treatment options depend on what stage the cancer has progressed to, whether there is ulceration at the primary site, the location and size of the tumor, and the individual's overall health.

Melanomas may be treated with surgery, chemotherapy, radiation, or biological therapy. Surgery is the most common method of treatment and may also include removal of the lymph nodes. Some adjuvant chemotherapy may be necessary to make sure that any cancer cells left in the body are killed.

Risk factors

Fair-haired, light-skinned people are more susceptible to melanoma, particularly those with blue, gray, or green eyes, red or blond hair, and lots of freckles. The risk increases for people who sunburn easily, particularly if they live in places where sunlight is intense. People with darker skin are not immune to melanoma.

Other risk factors include:

• Unusual moles
• Excessive exposure to natural sunlight
• Exposure to artificial ultraviolet light, such as a tanning bed
• Family or personal history of melanoma
• Being older than 20 years

Typical symptoms

Possible signs of melanoma include a change in the appearance of a mole or pigmented area. Consult a doctor if any of the following conditions occur in a mole or pigmented area:

• The size, shape, or color changes
• Irregular edges or borders develop
• A mole divides or becomes asymmetrical
• Itching, oozing, bleeding, or ulceration occurs
• New moles develop near an existing mole

Diagnosing melanoma

A melanoma diagnosis usually begins with a skin examination. A doctor checks whether a mole, birthmark, or other pigmented area looks abnormal. If it does, various tests and procedures are carried out to detect melanoma. Until a diagnosis is confirmed, do not disturb suspicious areas by shaving, scratching, or rubbing.

Standard diagnostic tests include:

• Biopsy: A biopsy is a local excision that is done to remove as much of the suspicious mole or lesion as possible. A pathologist then looks at the tissue under a microscope to check for cancer cells. Because melanoma can be hard to diagnose, consider having a biopsy sample checked by a second pathologist.
• Chest x-ray: An x-ray of the organs and bones inside the chest.
• CAT scan: A CAT scan is a procedure in which a computer linked to an x-ray machine takes pictures of areas inside the body at different angles. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. For melanoma, pictures may be taken of the chest, abdomen, and pelvis.
• Lymph node mapping: Procedure in which a radioactive substance and/or blue dye is injected near the tumor. The substance flows through lymph ducts to the sentinel nodes, which are the first lymph node or nodes where cancer cells are likely to have spread.
• MRI: An MRI is a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body.
• PET scan: A PET scan is a procedure to find malignant tumor cells in the body. A small amount of radionuclide glucose is injected into a vein. The PET scanner rotates around the body and takes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and use more glucose than normal cells.

Determining the stage

Once melanoma is diagnosed, tests are performed to find out if cancer cells have spread within the skin or to other parts of the body. This process is called staging, because it lets doctors know what stage the cancer is at in order to plan treatments.

The four stages of melanoma are:

• Stage 0 - Melanoma is found only in the epidermis, or outer layer of the skin. This stage is also called melanoma in situ.
  

• Stage I - In stage IA, the tumor is no more than one millimeter thick, has no ulceration, and is found only in the epidermis and upper layer of the dermis. In stage IB, the tumor is one to two millimeters thick, with or without ulceration, and may have spread into the tissues below the skin.
  

• Stage II - In stage II, the tumor is no more than four millimeters thick and may or may not have ulceration. Stage II tumors divide into three further classifications, depending on the thickness and spread of the tumor.
  

• Stage III - In stage III, the tumor may be any thickness, with or without ulceration, and has spread to either the lymph nodes or lymph system.
  

• Stage IV - In stage IV, the tumor may be any thickness, with or without ulceration, and has spread to one or more nearby lymph nodes or other parts of the body.

See also

• Clinical trials
• Latest cancer news and research
• Conventional treatment options
• Planning your treatment