Giant Brunner's gland hamartoma of the duodenal bulb removed by endoscopic submucosal dissection.

A duodenal Brunner’s gland hamartoma is an extremely rare benign tumor of the duodenum, representing less than 1 % of primary tumors of the small intestine [1]. Most patients are asymptomatic, but sometimes the condition can cause symptoms such as obstruction or gastrointestinal hemorrhage [2]. In symptomatic patients, endoscopic or surgical treatment is required. When possible, endoscopic management is the first-line treatment, especially for pedunculated lesions [3].