Introduction: Duodenal duplication is a rare congenital malformation and has been reported as a rare cause of recurrent acute pancreatitis. Hemorrhagic ascites has been reported in only one case of duodenal duplication.
Case presentation: An 11-year-old Chinese girl presented with abdominal pain, hematemesis and dark stools. On admission, an abdominal examination revealed a moderately distended abdomen with diffuse tenderness. Biochemical investigations showed increased serum levels of amylase, lipase, and urine amylase. An abdominal computed tomography scan and magnetic resonance imaging scan revealed an enlarged and heterogeneous pancreas with poorly delineated borders. There was a cystic lesion measuring 25mm × 48mm × 28mm, located between the descending portion of her duodenum and the head of her pancreas. There were massive effusion signals in her abdominal cavity. An exploratory laparotomy was performed. A tubular cyst measuring 32mm × 52mm × 30mm was found in the second part of the duodenum, next to the head of her pancreas. The anterior wall of the duplication cyst was resected and anastomosis of the remaining cyst to the duodenum was performed for drainage. Histopathological examination of the excised cyst wall showed duodenal mucosa, submucosa and muscle coats, indicative of a duodenal duplication.
Conclusions: It is important to be aware of duodenal duplication when evaluating a patient with recurrent acute pancreatitis accompanied by massive hemorrhagic ascites.