Freckle on Lip: Meaning, Causes and Is It Dangerous? (Labial Melanotic Macule) La Bouche Parfaite Pigmented Lesions of the Oral Mucosa: Clinical Presentation, Histology, and Recommendations for Management American Journal of Clinical Dermatology Springer Nature Link Melanosis coli: Symptoms, causes, treatment, and more 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 Melanocytic Naevus Ballarat Skin Cancer Centre Oral Mucosal Melanosis IntechOpen