Adenomyomatous hyperplasia of the papilla of Vater: A sequela of chronic papillitis?

A case of adenomyomatous hyperplasia of the papilla of Vater is described. The lesion presented as a small polypoid tumor projecting into the duodenal lumen, causing obstruction and dilatation of the common bile duct. Serial cross-section of the ampulla showed diffuse thickening of the muscular layer corresponding to Oddi's sphincter, with resulting narrowing of the lumen. Many ductal or glandular components were dispersed within the mucosa and the muscular layer and were admixed with lymphocytes, a few lymphoid aggregates, and fibrosis. Based both on the absence of cellular atypia and the presence of inflammation, fibrosis, and preservation of the normal architecture of the ampulla, we favor the interpretation that this hyperplastic lesion represents a sequela of chronic papillitis. The different diagnoses for this lesion are presented along with a review of the literature.