Oral melanotic macula on the lower labial vestibular mucosa on a Download Scientific Diagram Lentigo maligna and lentigo maligna melanoma Oral Mucosal Melanosis IntechOpen What Is Melanonychia? What Causes It and How It's Treated 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 Neurocutaneous Melanosis (Neurocutaneous melanocytosis) Dermatology Advisor