Abstract
A pedunculated mass arising from the second portion of the duodenum was detected in a 66-year-old woman during a follow-up endoscopic examination after treatment of a gastric and duodenal ulcer. The mass was a soft, 3cm-sized, polypoid projection into the lumen and was overlaid by intact duodenal mucosa. When biopsied, clear fluid was exuded from the polyp. Endoscopic resection was performed with a preoperative diagnosis of cystic polyp of the duodenum. The resected specimen revealed a simple submucosal cyst containing clear mucinous fluid, and Brunner's gland hyperplasia was observed in the stalk of the polyp. The wall of the cyst was lined with a single layer of columnar cells, and it appeared to represent cystic change of Brunner's gland hyperplasia. In addition to our own case, 61 cases of Brunner's gland tumor have been reported in Japan in the last decade. We review them from the standpoint of cystic change, and have classified them into four histological categories.
