Mucosal melanocytic macules Labial Lentigo (labial melanotic macule) Cancer Therapy Advisor Oral Malignant Melanoma Oral Cancer Foundation Information and Resources about Oral Head and Neck Cancer Melanotic macule. Benign. Dark spot on labia (or lip). Analogous to lentigo simplex. Hyperpigmented basal keratinocytes & dermal melanophages. Slight in single basal melanocytes; NO nests. More info like this in A) Hairy black tongue. (B) Linea alba. (C) Oral melanotic macule. (D) Download Scientific Diagram 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