Common acquired nevi (moles) include junctional, dermal, and compound nevi, which are all considered benign. These distinctions are based upon the location of melanocytic nests in the epidermis, dermis, or both, respectively. Clinically, junctional nevi are flat (macular) whereas dermal and compound nevi are elevated relative to the surrounding skin (papular).

Nevi typically arise during childhood, adolescence, or very early adulthood and then senesce in later years. During pregnancy, existing nevi may darken and become noticeable to the patient. Compound nevi are more common in individuals with lighter skin phototypes; other forms of nevi (those on palms, soles, conjunctiva, and in the nail bed) are more common in individuals of African and Asian descent.