Irregular moles are also called atypical moles. Regular moles are typically benign and friendly. Regular moles are usually symmetrical, have regular borders, uniform color, and are about the size of a pencil eraser or smaller. Regular moles may be flat or raised. The presence of hair growing from a mole is unrelated to its cancer potential. Irregular or atypical moles are usually asymmetrical, with irregular borders, multiple colors, and tend to be bigger than the size of a pencil eraser. Irregular moles are often flat or nearly flat. Having more than 20-25 irregular moles may increase the person's overall risk of developing melanoma.