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 Labial Lentigo (labial melanotic macule) Cancer Therapy Advisor Pigmented Lesions of the Oral Cavity Pocket Dentistry A Fast Growing Black Patch on the Upper Front Gum: Malignant Melanoma Springer Nature Link