Pathology of ampullary tumors including intra-ampullary papillary-tubular neoplasm (IAPN) and site-specific subclassification

Abstract

Ampullary tumors arise in anatomically complex major duodenal papilla (papilla of Vater) so that show various pathological features. Ampullary adenomas or adenocarcinomas are mixed with various cell lineages (intestinal, pancreatobiliary or gastric type) even in a single tumor, but including those resembling colorectal adenoma or adenocarcinoma, those resembling pancreatobiliary intraductal papillary neoplasm, and those resembling ordinary pancreatic ductal carcinoma or bile duct carcinoma, showing each specific biological behavior. It is necessary to consider these differences and characteristics for the diagnosis and treatment of ampullary tumors.