Type III Choledochal Cyst Variant: First Description of a “Closed Choledochocele” with Biliary and Pancreatic Drainage Via the Accessory Duct

Abstract

Type III choledochal cysts, also called choledochoceles, are rare congenital or acquired malformations of the terminal biliary tree of unknown etiology. These cysts can predispose a patient to biliary colic, obstructive jaundice, or idiopathic recurrent pancreatitis through an obstructive mechanism as the normal flow of bile is disrupted. They have been described in two anatomic variants 1) both the pancreatic and bile ducts drain into the choledochocele 2) the choledochocele is a cystic outpouching into the duodenum proximal to a normal ampulla. Endoscopic ultrasound and ERCP are primary tools to help diagnosis these anomalous formations and needle-knife sphincterotomy has recently been used to treat these cysts in symptomatic patients. We report the case of a 23 year-old white female with no previous past medical history who developed acute pancreatitis two weeks after completing an unremarkable first pregnancy. On EUS, she was found to have a Type III choledochocele with no apparent drainage into the duodenum. Bile was seen draining from the accessory duct. Subsequent ERCP via the minor papilla revealed communication of the ventral pancreatic and common bile ducts within a choledochocele which did not communicate with the duodenum. The bile duct appeared to empty retrograde into the ventral pancreatic duct and subsequently out to the duodenum via the accessory duct. To facilitate biliary and pancreatic duct drainage, the choledochocele was accessed and opened with a needle-knife followed by biliary sphincterotomy and temporary plastic biliary stent placement. Six weeks following the procedure, she continues to feel well. This case represents the first description of a “closed choledochocele” with biliary and pancreatic drainage via the accessory duct.[figure1]Figure