Often the first sign of melanoma is a change in the shape, color, size, or feel of an existing mole. Melanoma may also appear as a new colored area on the skin.
The "ABCDE" rule describes the features of early melanoma:
- Asymmetry. The shape of one half does not match the other half.
- Border that is irregular. The edges are often ragged, notched, or blurred in outline. The pigment may spread into the surrounding skin.
- Color that is uneven. Shades of black, brown, and tan may be present. Areas of white, gray, red, pink, or blue may also be seen.
- Diameter. There is a change in size, usually an increase. Melanomas can be tiny, but most are larger than 6 millimeters wide (about 1/4 inch wide).
- Evolving. The mole has changed over the past few weeks or months.
Melanomas can vary greatly in how they look. Many show all of the ABCDE features. However, some may show only one or two of the ABCDE features.1 2 3
1. An uneven (asymmetric) melanoma with an irregular but distinct border. The melanoma is more than 20 millimeters wide (about the size of a postage stamp).
2. A blue-black melanoma that has irregular and scalloped borders. It has arisen from a dysplastic nevus (the pink-tan region at the upper left). The melanoma is about 12 millimeters wide (nearly 1/2 inch).
3. A melanoma with three parts—a dark brown or black area on the left, a red bump on the right, and an area that is lighter than the skin at the top. The melanoma is about 15 millimeters wide, or about as wide as a tube of lip balm.
Seeking Medical Attention
Check with your doctor if you notice any of the following changes
- A mole that:
- changes in size, shape, or color.
- has irregular edges or borders.
- is more than one color.
- is asymmetrical (if the mole is divided in half, the 2 halves are different in size or shape).
- oozes, bleeds, or is ulcerated (a hole forms in the skin when the top layer of cells breaks down and the tissue below shows through).
- A change in pigmented (colored) skin.
- Satellite moles (new moles that grow near an existing mole).
Last updated March 27, 2013.
Reference: National Cancer Institute
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