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 Nathan M. Albert, BS MDedge PDF] Pigmented lesions of the oral mucosa and perioral tissues: a flow chart for the diagnosis and some recommendations for the management. Semantic Scholar Primary Oral Malignant Melanoma Oral melanoacanthoma and oral melanotic macule: a report of 8 cases, review of the literature, and immunohistochemical analysis Pigmented Lesions of the Oral Mucosa Pocket Dentistry