Annular pancreas as a rare cause of gastric outlet obstruction in a 27-years-old male patient: a case report and review of the literature

Annular pancreas is a rare congenital anomaly in which pancreatic tissue partially or completely encircles the second portion of the duodenum, leading to gastric outlet obstruction (GOO). Though often diagnosed in infancy or childhood, symptoms can occasionally manifest in adulthood. Since this congenital condition is rare and lacks established treatment guidelines, we decided to present this case. We report a twenty seven-years-old black male patient from Ethiopia who presented with a complaint of worsening of vomiting for the past seven years. He also has history of early satiety, bloating, and burning type of epigastric pain and weight loss. Contrast-enhanced computed tomography (CT) was suggestive of gastric outlet obstruction Secondary to likely Annular pancreas. Laparotomy was done, and there was annular pancreatic tissue causing obstruction at second part of the duodenum, and a retro-colic gastrojejunostomy was successfully performed. The patient had an uneventful postoperative recovery with resolution of symptoms. The patient’s symptoms have improved and he is being followed as an outpatient. This case highlights the importance of considering annular pancreas as a differential diagnosis in adults presenting with gastric outlet obstruction, as it is typically diagnosed in infancy or early childhood, and emphasizes the role of surgical intervention in achieving favorable outcomes. The patient's diagnosis was delayed due to misinterpreted symptoms and limited resources. The successful surgical management in a resource-constrained setting highlights the importance of adaptable treatment strategies and raises awareness of annular pancreas in adults.