MDCT of biliary cysts in children with biliary atresia: clinical associations and pathologic correlations.

Biliary atresia is a liver disease of newborns in which there is obliteration of intrahepatic and extrahepatic bile ducts leading to progressive liver injury (1). It is the third most common cause of neonatal cholestatic jaundice and is the most common indication for liver transplantation in children (2). The etiology is unknown, but perinatal viral infections, genetic factors, defects in immune response, autoimmune disorders, and defects in morphogenesis of biliary tree have been postulated. The disorder is commonly classified as classic (or perinatal) type and the embryonic (or fetal) type. In the perinatal type, bile ducts are patent at birth. A progressive inflammatory and sclerotic reaction results in the eventual obliteration of the biliary tree. The consequence is the development of obstructive jaundice, indicated by direct hyperbilirubinemia and acholic stools. The embryonic or fetal type often is associated with other structural anomalies such as the polysplenia sequence, preduodenal portal vein, and situs inversus. In this setting, the extrahepatic biliary tree may not have formed (3). The prognosis of patients with biliary atresia has improved since the introduction of Kasai and Suzuki’s hepatic portoenterostomy in 1959 (4). Long-term follow-up has shown that intrahepatic cystic lesions develop after hepatic portoenterostomy in some patients. These cysts may be a source of recurrent infection and affect the morbidity and mortality of patients with biliary atresia (5–7). Although the clinical manifestations are clear, the cause of cyst formation in the biliary system is unclear. The aim of this study is to present multidetector computed tomography (MDCT) findings of biliary cysts and to evaluate the association of biliary cyst formation with cholangitis, portoenterostomy, biochemical abnormalities, and pathologic findings of end-stage liver disease.