The cause of extrahepatic biliary atresia (EHBA) is undetermined in most instances, but an infectious agent is widely suspected. Cytomegalovirus (CMV) infection has been associated with intrahepatic bile duct destruction and paucity, raising the question of its role in EHBA. We identified 12 children in the past 5 years with biliary atresia and examined the bile duct biopsy. These showed acute/chronic inflammation and epithelial degeneration. CMV inclusions were not identified. We used in situ hybridization and the polymerase chain reaction (PCR) for CMV-DNA on formalin-fixed, paraffin-embedded tissue. All samples showed the presence of amplifiable DNA using beta-globin primers. No biopsy tissue showed CMV DNA using specific probes and primers. The absence of demonstrable CMV DNA by in situ hybridization and PCR in EHBA biopsies implies that it is unlikely that this virus has any major role in the pathogenesis of this condition VSports手机版. .