"Duodenal intussusception" due to adenoma of the papilla of Vater.

The case of a 55-year-old woman with a pedunculate adenoma of the papilla of Vater is presented. Diagnostic imaging modalities including ultrasonography, CT scan, magnetic resonance of cholangiopancreatography, simultaneous duodenography and cholangiography, and angiography showed a giant tumor protruding intraluminally and moving forward in the duodenum by peristalsis. It had a duodenal intussusception-like appearance, with remarkable left-lower deviation of the common bile duct and major pancreatic duct in the papilla of Vater as far as the left side of the aorta. Episodes of jaundice or ileus were absent, probably because the tumor was mobile in the duodenum. As biopsy specimens showed no malignancy and intraductal ultrasonography in the common bile duct revealed no intraductal invasion of the tumor in the papilla of Vater, the patient underwent transduodenal papillectomy with papilloplasty with pancreatic ductoplasty. Pathological diagnosis of consecutive specimens was a papillary adenoma with moderate atypia and occasional tubular structure. There seems to be an exceptional subtype of the tumor in the papilla of Vater, like this case, demonstrating the duodenal intussusception-like appearance without prominent clinical symptoms.