Annular pancreas causing pyloric stenosis in a 66-year-old patient treated with gastrojejunostomy: a case report

Annular pancreas is defined by a ring of pancreatic tissue encircling the descending portion of the duodenum. It is exceptionally rare in adults and commonly diagnosed during the investigation of symptoms arising due to its complications. Treatment usually involves the surgical correction with a duodenoduodenostomy, gastrojejunostomy or duodenojejunostomy. We discuss the case of a 66-year-old male patient who presented with symptoms of gastric outlet obstruction and was found to have an annular pancreas encircling the pylorus and the first and second portions of the duodenum and was treated by performing a gastrojejunostomy. Upper gastrointestinal series, computerized tomography (CT) scans, and magnetic resonance cholangeopancreatographys can all be used for preoperative diagnosis; however, endoscopic retrograde cholangiopancreatography (ERCP) is the diagnostic modality of choice. Nonetheless, many patients may only be diagnosed intraoperatively, especially those who cannot undergo an ERCP due to stenosis proximal to the duodenum or patients in whom the annulus may not be visible on CT scan.