A Case of Ampullary Adenoma that Developed to Cancer 7 Years After Initial Diagnosis

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.