Oral Melanotic Macule MEDizzy Definition of melanocytic macules associated with Peutz Jeghers syndrome NCI Dictionary of Genetics Terms NCI Happy Wednesday! , In this video, a patients labial melanotic macule (a benign pigmented lesion) is being treated with liquid nitrogen. Labial melanotic macules are flat and asymmetrical with a Labial Lentigo (labial melanotic macule) Cancer Therapy Advisor 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