Diagnosis of congenital dilatation of the bile duct and pancreaticoobiliary maljunction

Abstract

Diagnostic procedures of congenital dilatation of the bile duct (CDBD) and pancreatobiliary maljunction (PBM) were reviewed. CDBD is classified into 5 types, from type I to V. US, CT, and MRCP can easily delineate the dilation of the bile duct except in patients with CDBD of type II and type III. MRCP, EUS, ERCP, and contrast-enhanced MDCT are useful to diagnose PBM observed in patients with CDBD of type Ia, type Ic, and type IV-A. Although MRCP is non-invasive and useful, it is necessary to perform EUS and/or ERCP to detect biliary tract cancer highly complicated with PBM. It is important to detect patients with PBM without dilatation of the common bile duct, because such patients have high incidence of biliary tract cancers. In such patients, diffuse thickening wall of the gallbladder and/or slight dilatation of the common bile duct are observed frequently. From the viewpoint of early detection or prevention of biliary tract cancer, we should diagnose carefully in patients with such findings.