Giant Brunner's Gland Adenoma of the Proximal Jejunum Presenting as Iron Deficiency Anemia and Mimicking Intussusceptions.

Brunner's gland adenoma is a rare benign proliferative lesion developing most commonly in the posterior wall of the duodenum. It is usually small in size and asymptomatic. Depending on its size or location, however, the clinical manifestations of this tumor may be variable from nonspecific symptoms to gastrointestinal bleeding or obstruction. Brunner's gland adenoma in the proximal jejunum is extremely rare. We report a very rare case of giant Brunner's gland adenoma developing in the proximal jejunum which presented as iron deficiency anemia and mimicked intussusceptions on radiologic studies.