A nevus, or mole, is a common skin growth looking like a darkly pigmented spot, usually raised above the surrounding surface, rough, and covered with hair. Malignant growths my spring from them late in life.
Nevi are composed of special pigment-producing cells called nevomelanocytes. Nevomelanocytes are related to pigment producing cells normally found in the skin, called melanocytes. A congenital nevus is a mole present at birth.