| Abstract: | A case of duodenal neoplasm in the second portion of the duodenum is presented. Endoscopically, the lesion was characterized by a broad‐based, submucosal tumor‐like protrusion with a shallow central depression. The lesion was successfully removed by endoscopic mucosal resection. Histological examination of the resected specimen revealed the lesion to be composed of Brunner's gland hyperplasia in the submucosal layer and adenomatous glands in the mucosa. Our case suggests that neoplastic transformation possibly occurs in Brunner's gland hyperplasia. |
