title: Occult duodenal Zollinger-Ellison tumors: their diagnosis by gastrin radioimmunoassay.
mesh_terms: D007516:Adenoma, Islet Cell / Q000175:diagnosis; D004379:Duodenal Neoplasms / Q000175:diagnosis; D005755:Gastrins; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D011863:Radioimmunoassay; D015043:Zollinger-Ellison Syndrome / Q000175:diagnosis*
chemical_list: D005755:Gastrins