What is atypical moles?

Skin cells that produce pigment (melanocytes) sometimes group together to form moles. Melanocytes can form abnormal moles, also called atypical moles or dysplastic nevi.

These moles are not skin cancer. But their presence is a warning of an inherited tendency to develop melanoma. Some people have only 1 or 2 atypical moles. Some people may have more than 100. The tendency to develop atypical moles can run in families (inherited predisposition).

Atypical moles are seen most commonly on the back but may be anywhere on the body, including below the waist, on the scalp, or on the breasts or buttocks.

Atypical moles can look like melanoma. They may:

• Be dark brown, black, or have more than one color.
• Have uneven edges or a shape that isn't the same on both sides.
• Be smooth, slightly scaly, or have a rough, irregular, "pebbly" appearance.
• Change in size or shape, or grow larger than other moles.

Atypical moles usually are not present at birth but develop some time later.