2014 Volume 56 Issue 7 Pages 2163-2170
An 86-year-old man was found to have a duodenal submucosal tumor (SMT)-like lesion by esophagogastroduodenoscopy (EGD) that was classified as an adenocarcinoma based on a biopsy specimen. He was referred to our hospital for further examination and treatment. The tumor was located on the second part of the duodenum and had a depression on its apical surface. It was identified as an early carcinoma by duodenography, endoscopic ultrasonoscopy, and computed tomography (CT). Based on these findings, we treated the patient with endoscopic mucosal resection (EMR). Histological examination of the resected specimen revealed a well differentiated tubular adenocarcinoma that had invaded the submucosa, but not the lymphatic vessels or vessels. Histologically, the adenocarcinoma originated from hyperplasic Brunner's glands, and therefore we diagnosed it as a duodenal adenocarcinoma of Brunner's gland origin. Immunohistochemical staining indicated positive results for gastric mucin markers such as MUC5AC and MUC6, and negative results for intestinal mucin markers such as MUC2 and CD10. Thus, his duodenal tumor was believed to be a duodenal carcinoma arising from Brunner's glands.
