A very low-birth-weight infant with spontaneous perforation of a choledochal cyst and adjacent pseudocyst formation.

Spontaneous perforation of a choledochal cyst with ensuing pseudocyst formation is a very rare complication. We report the development of a pseudocyst adjacent to a choledochal cyst in a very low-birth-weight infant at 2 months of age. Elective excision of the choledochal cyst and biliary tract reconstruction were successfully performed 2 months later when the infant weighed 3 kg. Delayed primary repair may be a viable alternative treatment for low-birth-weight infants with choledochal cysts.