ABSTRACT
Cystic dilatation of the extrahepatic bile ducts is a rare abnormality in Western countries, with an incidence which has been estimated at around 1 in 15 000 live births.1 The incidence is much higher in the Far East, and in Japan choledochal cysts may account for up to 1 per 1000 hospital admissions. The male to female ratio has been variably reported as being between 1:2 and 1:4.2,3 More than 60% of cases present before the age of 10,4,5 and an increasing number are presenting antenatally as a result of routine ultrasound scanning.6-8
History
Abnormalities in the anatomy of the common bile duct were originally described by Vater,9 but Douglas10 gave the first detailed account of a patient with massive dilation of the bile duct. He described a 17-year-old girl with the now classic triad of pain, jaundice and a right-sided abdominal mass. This was managed by percutaneous aspiration of 900 ml of bile, but unfortunately the girl died 1 month later. The subsequent postmortem examination confirmed the presence of a choledochal cyst.
