Spontaneous rupture of a choledochal cyst: clues to diagnosis and etiology.

A healthy 3-year-old black girl had acute onset of abdominal pain, vomiting, and elevated aminotransferase, amylase, and lipase levels. Sonographic evaluation suggested a choledochal cyst, but hepatobiliary scintigraphy clearly showed an extrahepatic biliary leak. Exploratory laparotomy confirmed bile peritonitis and a ruptured choledochal cyst. Other cases with this unusual presentation is reviewed in the literature. An anomalous insertion of the pancreatic duct into the common duct appears to facilitate reflux of pancreatic secretions into the biliary tree and may contribute to formation and even perforation of a choledochal cyst.