Lingual melanotic macule the first case report in an adult patient* Anais Brasileiros de Dermatologia A Rare Case of Oral Mucosal Pigmentation: Differential Diagnosis and Case Presentation JCDA Smoker? These brown patches might NOT be dangerous Most dental students confuse this condition Smoker's melanosis is a common oral finding caused by increased melanin production due to tobacco exposure 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.