Annular Pancreas: A Rare Cause of Upper Gastrointestinal Bleeding in Adults.

Annular pancreas is a rare congenital anomaly in which a thin band of pancreatic tissue partially or completely surrounds the duodenum. It is challenging to diagnose due to its variable clinical presentation. Approximately two-thirds of patients have no symptoms in their lifetime, and most symptomatic cases are seen in neonates and infants. Symptomatic adult patients present with upper gastrointestinal symptoms, such as epigastric pain, vomiting, and postprandial fullness associated with gastric outlet obstruction. Complications associated with annular pancreas include peptic ulcer disease, pancreatitis, pancreatic head carcinoma, and biliary obstruction. Annular pancreas is also a rare cause of upper gastrointestinal bleeding in adults, but it should be considered as one of the differential diagnoses in patients presenting with a peptic ulcer and duodenal stricture. Here, we report the case of a 60-year-old man who presented with melena and was subsequently diagnosed with an annular pancreas.