Department of Obstetrics and Gynecology,  McMaster University/St. Joseph's Hospital, Hamilton, Ontario  Canada,  (905) 521-2100 ext 76245

Definition A choledochal cyst is a rare disorder of the biliary tree in which there is cystic dilatation of the common bile duct.

Case report

This case involves a 34-year-old gravida 3 term 2 women carrying an infant with these ultrasound findings at 24 weeks gestation. The choledochal cyst is apparent and its location is identified by its relationship to other structures in the vicinity (gallbladder, hepatic portion of umbilical vein, inferior vena cava). Labor was induced for intrauterine growth restriction at 38 weeks gestation. The infant weighed 2880g and Apgar scores of 9 at one minute and 9 at five minutes were given.

The newborn infant was followed by a pediatric surgeon and underwent surgery at approximately ten months of age. The surgery included excision of the choledochal cyst and gallbladder and reconstruction of the biliary tree with a Roux-en-Y anastomosis. The cyst was noted to join the pancreatic ductal system. The pathology report identified a normal gallbladder and the choledochal cyst

Etymology Gr. cole, bile + doceion, a receptacle, a holder, thus: coledocos  "containing bile".

History First demonstrated antenatally by Dewbury in 1980¹.

Prevalence Eighteen other cases have been diagnosed antenatally as summarized by Benhidjeb² and Gallivan³. The estimated incidence is 0.005:10,000 live births¹.

Etiology Unknown.

Pathogenesis There are two primary theories. One described by Yotsuyanagi⁴ suggests an inequality in vacuolization of the biliary tree in early embryonic life. Babbit⁵ proposed that the origin is an anomaly of the pancreatico-biliary junction and the subsequent formation of a long common duct. This may then lead to formation of a cyst as pancreatic juice refluxes causing inflammation and weakening of the wall of the bile duct.

Sonographic appearance: A cystic structure is seen in the right upper quadrant connected to the gallbladder via the cystic duct in the region of the porta hepatis

Differential diagnosis Hydronephrosis, duodenal duplication, intestinal atresia, mesenteric cyst, ovarian cyst, choledochal cyst

Prognosis Complications such as cholangitis, liver abscesses, portal hypertension, pancreatitis, liver failure, cirrhosis and malignant degeneration may occur if the cyst is not excised.

Management Surgical excision of the cyst and reconstruction of the biliary tree with a Roux-en-Y anatomosis

References

See also 2000-07-04-18 Choledochal cyst © Valero www.thefetus.net/

1) Dewbury KC, Aluwihare AP, Birch SJ, Freeman NV. Prenatal ultrasound demonstration of a choledochal cyst. Br J Radiol. 1980 Sep;53(633):906-7.

2) Benhidjeb T, Chaoui R, Kalache K, Mau H, Muller JM Prenatal diagnosis of a choledochal cyst: a case report and  review of the literature. Am J Perinatol. 1996 May;13(4):207-10.

3) Gallivan EK, Crombleholme TM, D"Alton ME. Early prenatal diagnosis of choledochal cyst. Prenat Diagn. 1996 Oct;16(10):934-7.

4) Yotsuyanagi S Contributions to etiology and pathogeny of idiopathic cystic dilation  of the common bile duct Gann 1936;30: 601-51

5) Babbitt DP. Congenital choledochal cysts: new etiological concept based on anomalous  relationships of the common bile and pancreatic bulb Ann Radiol 1969; 12:231-40