Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Pigmented Lesions and Melanoma Plastic Surgery KeyPlastic Surgery Key Lingual melanotic macule the first case report in an adult patient* Anais Brasileiros de Dermatologia Brown spots, especially on the lips, can be alarming to some. In some instances it can indicate rare oral mucosal melanoma, however in this case it was a non cancerous labial melanotic macule. Oral Mucosal Melanosis IntechOpen