A mole (pigmented skin lesion).
A nevus may turn into a cancer (melanoma). Children with a nevus are at increased risk of developing skin cancer as adults.
A nevus can occur anywhere on the skin or in the eye. It's usually brown and can be smooth, wrinkled, flat, or raised. It may have hair growing from it.
Treatment usually isn't necessary, but a nevus that changes shape, grows bigger, or darkens should be evaluated for removal.