title: Hematemesis in an adolescent.
mesh_terms: D000293:Adolescent; D000367:Age Factors; D004381:Duodenal Ulcer / Q000453:epidemiology*; D006396:Hematemesis / Q000209:etiology*; D006801:Humans; D008297:Male; D010438:Peptic Ulcer Hemorrhage / Q000453:epidemiology*