A case of Brunner's gland hamartoma developing jejunoduodenal intussusception and profuse melena

A 25-year-old man complaining of emesis and anemia was referred to our hospital on suspicion of pyloric stenosis. Endoscopic examination revealed the stenosis of the pylorus, but the endoscope passed through it without difficulty. A retroperitoneal tumor was suspected based on the abdominal CT scan findings, a definite diagnosis was impossible and while undergoing other examinations, the patient unexpectedly developed acute profuse melena. Angiography revealed no significant source of bleeding, and his anemia progressed. Finally, exploratory laparotomy was performed. A polypoid tumor with a maximum diameter of 5 cm was found to arise from the posterior aspect of the first portion of the duodenum to distal to the ligament of Treitz and causing retrograde jejunoduodenal intussusception with the proximal jejunum into the third portion of the duodenum. The source of the hemorrhage was the leading tumor and the tumor was histologically diagnosed as a Brunner's gland hamartoma. Anatomically the intussusception of the duodenum is quite rare. Classification of duodenal intussusception, the mechanism of it and the X-ray findings were discussed.