A benign hyperpigmentation of the mucous membranes. Presents as a solitary, flat, brown or grayish-brown discoloration of the lip, typically on the vermillion border, but may also occur on an intraoral mucosal surface. May be multiple. Appears slowly and has a uniform color and border. Typically 2-15 mm in diameter. In general, the darker the skin type, the more likely the patient is to develop mucosal melanotic macules. Although benign, biopsy may be needed to rule out a diagnosis of melanoma.