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.
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.
Risk Factors
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
Symptoms
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, dark, 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.
Bleeding—The mole may start to itch, or it may ooze or bleed in more advanced cases.
Diagnosis
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 melanoma. The doctor may need to remove a sample of lymph node tissue to test for cancer cells.
Treatment
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.
Treatments include:
Surgery
Surgery involves the
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
This treatment 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
Also called
biological response modifier (BRM) therapy, biological therapy involves medications or substances made by the body to increase or restore the body's natural defenses against cancer. Examples include interferon, interleukin 2, and melanoma vaccines.
Radiation Therapy (Radiotherapy)
Radiation therapy is
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.
Prevention
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.
RESOURCES:
American Academy of Dermatology http://www.aad.org
American Cancer Society http://www.cancer.org
Skin Cancer Foundation
http://www.skincancer.org/
CANADIAN RESOURCES:
Canadian Dermatology Association http://www.dermatology.ca/english/
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
