Clinical Definition

A mole, or pigmented nevus, is a dermatological growth, typically unicolor, most often brown but sometimes other hues or colorless. Most moles are benign, but changes in color, height, size or shape demands evaluation, as do nevi that bleed, ooze, itch, have a scaly appearance or become tender or painful. Some types of moles increase the risk of melanoma.

In Our Own Words

A mole, known medically as a nevus, is a skin growth that is usually flesh-colored, brown or black, but can be colorless, usually appearing in early childhood or before age 21. Some moles, called congenital, are present at birth. Others, called dysplastic nevi, are larger than normal and irregularly shaped. People with dysplastic nevi, especially if multiple, are at higher risk for melanoma.

Typically, a person can have 10 to 40 moles by adulthood. Most are not cancerous, but a medical evaluation is needed when there are concerning signs, including: if a mole looks asymmetrical, has a ragged or blurred border, the color is inconsistent throughout or changes, or if the mole diameter is larger than a pencil eraser.

If a mole is concerning, a biopsy (small sample) can be removed and examined under a microscope, or the entire mole may be removed, along with a margin, and the skin stitched closed.