BACKGROUND: Although ampullary adenomas have been reported to be considered as precancerous lesions, there have been very few reports of cases in which cancer occurred after long-term follow-up. We herein report a case of ampullary adenoma that developed to cancer after long-term observation.

CASE REPORT: An 81-year-old man was referred to our hospital due to a tumor at the ampulla of Vater. Histological examination revealed a tubular adenoma. Because the patient refused treatment, follow-up by duodenoscopy, EUS, MRCP, and forceps biopsy was planned. There was no change in the tumor for 6 years. Seven years after the initial diagnosis, he developed from jaundice. Duodenoscopy showed an easy-bleeding, reddish, uneven surface area of the tumor and NBI demonstrated an irregular, non-structured surface pattern. EUS demonstrated invasion of the duodenal muscularis and infiltration into the bile duct. Histological examination revealed a well-differentiated adenocarcinoma.

CONCLUSIONS: The clinical course of this case provides evidence of the adenoma-carcinoma sequence.

Keywords: Adenoma - pathology, Adenocarcinoma - pathology, Aged, 80 and over, Ampulla of Vater, Common Bile Duct Neoplasms - pathology, Time Factors