Melanomas usually have a shape that is asymmetrical (not the same on both sides), with uneven borders and patchy coloring. They normally measure more than 1/4 inch across.
It is important to know the difference between an ordinary, harmless mole and a mole that can grow into melanoma. An ordinary mole is usually an even-colored brown, tan, or black spot on the skin. It can either be flat or raised, round or oval. Ordinary moles are generally smaller than a pencil eraser. They may be present at birth or appear during childhood or adulthood. Several moles may appear on the skin at the same time, especially on areas of the skin that receive a lot of sunlight. Ordinary moles usually stay the same size, shape, and color for many years.
Moles that develop into melanoma have certain unusual features. They tend to look different from ordinary moles. A good way to remember what to look for is “ABCDE.”
Asymmetry
Melanomas are generally asymmetric, meaning that one side of the mole looks different from the other. Ordinary moles are usually symmetric, either round or oval.
Borders
Melanomas have uneven borders (edges) that are ragged, notched, or blurred. Ordinary moles have even borders.
Color
Melanomas have uneven coloring. They may have patchy areas of brown, blue, red, tan, white, gray or pink. Ordinary moles are usually an even shade of brown or tan.
Diameter
Melanomas are usually more than 1/4 inch in diameter (about the size of a pencil eraser) but some may be smaller. Ordinary moles are usually smaller and stay the same size and shape.
Evolution
Melanomas usually change in size, shape, or color over a short period of time. Ordinary moles stay the same size, shape, and color for many years.
