Melanoma Northwestern Medicine GASTROINTESTINAL HEMORRHAGE (2): Melena. Melena, the passage of black, tarry stools, usually implies blood loss greater than 500 ml originating anywhere between the oropharynx and the right hemicolon. Melena occurs most often, Oral Melanotic Macule: Symptoms and Treatment Skinsight Labial or Oral Melanotic Macule Benign, asymptomatic, and often underdiagnosed. Swipe to learn how to recognize, diagnose, and manage this simple yet important lesion! #thebasicdentist #rguhs #kuhs #tnmgrmu #OralPathology #MelanoticMacule #DentalFacts ORAL MELANOTIC MACULE (OMM) (Also called focal melanosis labial melanotic macule) A benign, localized, flat pigmented lesion of the oral mucosa Caused by a focal increase in melanin production