Labial melanotic macule Pigmented Oral Lesions: Clues to Identifying the Potentially Malignant Consultant360 ORAL MELANOTIC MACULE (OMM) (Also called focal melanosis labial melanotic macule) A benign, localized, flat pigmented lesion of the oral mucosa Caused by a focal increase in melanin production Definition of melanocytic macules associated with Peutz Jeghers syndrome NCI Dictionary of Genetics Terms NCI