Moles are a common type of growth found on the skin, and are caused by an overgrowth of melanocytes, pigment producing cells of the skin. They often appear as small, dark brown spots and are usually round or oval in shape. They may be present at birth (congenital nevi) or appear later in life (acquired nevi). Acquired nevi generally appear during childhood and adolescence. Most people have between 10 to 45 moles, almost all of which appear before the age of 40. Some moles may fade or disappear with age.
Moles vary in color; they can be pink, tan, brown, and even black. They can be small or large, flat or raised, and smooth or hairy. They can occur on any part of the body.
Moles may darken after exposure to the sun and during pregnancy.
Most moles are harmless, or benign, and do not require treatment. Rarely, they become atypical, or dysplastic; most worrisome is the development of cancerous moles, referred to as malignant melanoma.
Moles that are more likely to be atypical or cancerous are those that look different than other existing moles or those that appear after the age of 30. If you notice changes in a mole’s color, size, border, or shape, you should see a dermatologist for evaluation. You should also be wary of moles that spontaneously bleed, ooze, itch, or become tender or painful.
The following worrisome characteristics, referred to as the ABCDEs of moles, are important to consider when examining nevi.
Clinical monitoring of nevi by your dermatologist is an important part of skin cancer prevention; biopsy of concerning lesions can be performed, leading to the early diagnosis of malignant melanoma.