ERCP と管腔内超音波（IDUS）による十二指腸乳頭部腫瘍の診断

The ampulla of Vater (ampulla) has anatomical features that are not found in other portions of the gastrointestinal tract. The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct. Although consensus is being obtained for local excision including endoscopic ampullectomy for the treatment of adenomas that do not extend into the biliary and pancreatic ducts, pancreatoduodenectomy is basically recommended for the treatment of adenocarcinoma because of the difficulty in diagnosis of invasion into the sphincter of Oddi. It is also problematic that the pathological diagnosis of biopsy samples and that of resected samples are often different. The indication of endoscopic ampullectomy has to be determined by considering the findings of endoscopy, endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS). We will illustrate the actual diagnostic procedure of ampullary tumors (adenoma and adenocarcinoma) focusing on the indication of endoscopic ampullectomy.