A case of primary mucosal cancer of duodenum bulb

A 67-year-old man was referred to our hospital for follow-up after colonoscopy. Screening endoscopy showed a small (8mm) elevated lesion at the anterior wall of duodenum bulb. Magnifying view with Narrow Band Imaging (NBI) showed abnormal micro vessels. The biopsy tissue was diagnosed as group 4, and Endoscopic Mucosal Resection using a cap-fitted panendascope was performed. The resected specimen was finally diagnosed as well differentiated (papillary) adenocarcinoma, with horizontal positive margin. Therefore, careful follow up is necessary. Primary duodenal cancer was very rare and difficult to distinguish from adenoma. Magnifying view with NBI was effective. We show 12 cases of past duodenal cancer in 2005-2015. In most of the cases, tumors were located in duodenal bulbs and morphological type was IIa.