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 Oral pathology: Noting a pigmented macule that often presents a diagnostic dilemma Registered Dental Hygienists Oral melanotic macula on the lower labial vestibular mucosa on a Download Scientific Diagram Pigmented Lesions of the Oral Mucosa Springer Nature Link