A 8-year-old girl with the complaints of fever, upper abdominal pain, nausea and diarrhea was admitted at Niigata University Hospital on June 24, 1984. Diagnosis of congenital choledochal cyst was confirmed by ultrasonography and computed tomography. Endoscopic retrograde cholangiopancreatography through the major papilla vateri under general anesthesia, revealed cystic dilatation of the choledochus without showing pancreatic duct. Endoscopic retrograde pancreatography through the orfice of the minor papilla disclosed the Santorini duct and dorsal pancreatic duct without communication to the dilated choledochus. This evaluation led to the diagnosis of congenital choledochal cyst with pancreatic malfusion. Primary excision of the choledochal cyst and Roux-en-Y hepaticojejunostomy were performed on June 29, 1984. Postoperative course was uneventful and she was discharged on the 15th postopsrative day. In this case, congenital stenosis of the distal choledochus, malformation of the choledocopancreatic duct system and inflammation are etiologically suggested to be the cause of the congenital choledochal cyst.
