A large intrahepatic duodenal duplication cyst in a 3 year-old girl

•Intrahepatic duodenal duplication cyst is a very rare case.•First case of an intrahepatic duodenal duplication cyst in a pediatric patient.•Roux-en-Y cystojejunostomy was performed after resecting the stalk.•A review of the literature of this rare condition was performed.

Duodenal duplication cyst consists 6% of alimentary tract duplications and the prevalence is estimated to be less than 1 per 100,000 live births. This report is the first case report in a pediatric patient. A 19-month-old female patient was detected with a 5.2 cm sized intrahepatic cystic lesion in her follow-up ultrasonography examination for hydronephrosis. In her regular check-up, findings suggestive of food materials were detected inside the cyst. Further evaluation showed a 7 cm sized cyst located inside segment IV of the liver, connected to the duodenal bulb with a possibility of biliary communication. On exploration, duodenal duplication cyst with a 1.5 cm long stalk starting from the duodenal bulb to the hilum of the liver was identified. Due to its sophisticated location and possible communication with the biliary tree, Roux-en-Y cystojejunostomy was performed after resecting the stalk. The histopathologic finding of the stalk showed serosa, muscle, submucosa and duodenal mucosa which suggested its duodenal origin. The patient has been followed up without any complications for 7 months.