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 The Prevalence of Oral Pigmented Lesions among Sample of Dental Students. A Rare Case of Oral Mucosal Pigmentation: Differential Diagnosis and Case Presentation JCDA Dermoscopy of pigmented oral lesions; A research study ScienceDirect Dermoscopic Evaluation Improves Clinical Diagnosis of Oral Melanotic Macules: A Study in 50 Patients with Oral Pigmented Lesions American Journal of Oral Medicine