A Case of Primary Duodenal Adenocarcinoma in the Fourth Portion

: A 66-year-old woman admitted for nausea was found to have a type 2 tumor with stenosis at the fourth portion of the duodenum by upper gastrointestinal series and endoscopy, which was diagnosed as an adenocarcinoma by endoscopic biopsy. Abdominal computed tomography(CT)showed an irregular thick wall at the fourth portion of the duodenum but without metastasis or invasion to the adjacent vessels. We examined the lymph nodes around the pancreatic head intraoperatively and partially resected the duodenum and jejunum based on the diagnosis of negative swollen nodes. The definitive diagnosis was primary tubular adenocarcinoma of the fourth portion of the duodenum, T3, N0, M0, Stage ⅡA. Reports of primary cancer of the fourth portion of the duodenum are very rare, and we include a discussion of the current literature.