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 Spotty lips. These are labial melanotic macules, kinda like freckles on the lips. They are mostly due to age and sun exposure, but sometimes they run in families and are associated with Oral Melanotic Macule: Symptoms and Treatment Skinsight Pigmented Oral Lesions: Clues to Identifying the Potentially Malignant Consultant360 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