Melanoma, which means "black tumor," is a skin cancer that begins in cells called melanocytes. These cells produce the dark, protective pigment called melanin. It is melanin that gives skin its color.
Melanoma is the most dangerous type of skin cancer. Because melanocytes are involved, most melanomas are black or brown in color. However, if the cancerous cells stop producing pigment, a melanoma may be skin-colored, pink, red, or purple.
Melanoma can affect any area of the body. Men are more prone to melanoma on the trunk whereas women are more likely to have melanoma develop on the arms and legs.
About 30% of melanomas begin in existing moles (darkened spots on the skin). Skin melanoma grows quickly and has the ability to spread to any organ. Early detection is especially important with melanoma, because treatment success is directly related to the size and depth of the cancerous growth. Some melanomas grow outward on the surface of the skin and some spread vertically into the deep skin layers.
How common is melanoma?
Melanoma constitutes about 4% of all skin cancers. However, it accounts for more than 80% of skin cancer-related deaths and 1% to 2% of all cancer deaths in the United States. Melanoma usually occurs in adults, but it occasionally is found in children and adolescents. It is the most common cancer in women ages 25 to 29, and the second most common cancer in women ages 30 to 34, as well as in men ages 30 to 49.
What causes melanoma?
Most experts agree that the main cause of skin cancer is overexposure to sunlight, especially when it results in sunburn and blistering. Researchers believe that ultraviolet (UV) rays from the sun damage the skin and, over time, lead to skin cancer.
Although anyone can develop melanoma, the following groups of people have an increased risk for developing the disease:
- Personal history (have had melanoma before)
- People with fair skin, freckles, blond or red hair, and blue eyes
- People with a history of prolonged or excessive sun exposure, including blistering sunburns, in youth
- People with a history of tanning bed use
- People with many moles, especially “atypical” moles
- People with a family history of melanoma
- People with weakened immune system
Although malignant melanoma is more common in Caucasians, melanoma can occur in people of all skin types. Melanoma in nonwhite individuals most often occurs on the skin with less pigment, such as palms, soles, nails and mucous membranes.
What are the signs of melanoma?
The most common warning sign of skin cancer is a change in the skin, especially a new growth or a sore that doesn't heal. Some skin cancers can appear as moles, scaly patches, open sores, or raised bumps. Tell your doctor about any sores that won't go away, unusual bumps or rashes, or changes in your skin or in any existing moles.
The American Academy of Dermatology's "ABCDE" is a useful and easy-to-remember mnemonic for early melanoma detection. ABCDE stands for:
- Border — The border, or edges, of the mole are ragged, notched, or blurred.
- Color — The color of the mole is mottled and uneven, with shades of brown, black, gray, red, and white.
- Diameter — The size of the mole is usually large, greater than the tip of a pencil eraser (6.0 mm).
- Evolving — The mole changing in size, shape, or color or a new mole.
Some melanomas do not fit the ABCDE rule, so it is very important to be aware of any changes in the mole or any area of your skin. Another tool that can be used to recognize melanoma is the “ugly duckling” sign. It is based upon the observation that most moles are similar-looking to each other. The mole that looks different from that of surrounding moles is the ‘ugly duckling.’