Adenoma of the papilla and ampulla--premalignant lesions?

Ampullary adenomas arising in the papilla or the ampulla Vateri, are rare, benign, neoplastic lesions. No specific aetiological factors, such as diet, chemical or environmental causes, have been identified yet. An established risk factor which is accompanied by the development of adenoma is the presence of genetically inherited polyposis syndromes, e.g. familial adenomatosis coli (FAP). Adenomas assume tubular, tubulovillous, or villous architecture and are not different from adenomas arising elsewhere in the gastrointestinal tract. The full neoplastic spectrum, ranging from mild to high grade dysplasia, up to invasive carcinoma, resembles the adenoma-carcinoma sequence of the large bowels.