title: Nonfunctioning islet cell tumor presenting as gastrointestinal bleeding.
mesh_terms: D007516:Adenoma, Islet Cell / Q000150:complications*; D006471:Gastrointestinal Hemorrhage / Q000209:etiology*; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008551:Melena / Q000209:etiology; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000150:complications*