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, Mole or nevus, what is, what treatment? Visual assessment of melanoma Melanocytic Lesions Part 3 Deep learning finds convergent melanocytic morphology despite noisy archival slides ScienceDirect