Standardized Diagnosis and Treatment of Pancreaticobiliary Maljunction

According to extensive case analyses compiled by the Japanese Study Group on Pancreaticobiliary Maljunction (JSPBM), patients with Pancreaticobiliary Maljunction (PBM) exhibit a significantly elevated incidence of biliary tract tumors, ranging from 34% to 39%. This rate is dramatically higher than the population-based incidence of biliary tract tumors in the general population (approximately 0.002%). Beyond malignancy, PBM is associated with multiple common pancreatobiliary disorders, including recurrent pancreatitis, stones within the common pancreatobiliary channel, and pancreatic duct stones, which substantially impair patients' quality of life. Despite its insidious nature and frequent delayed or missed diagnosis, key clinical features such as recurrent pancreatitis, acalculous cholecystitis, and extrahepatic bile duct dilation provide crucial diagnostic clues. Standard diagnostic modalities include abdominal ultrasound, computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP). Endoscopic retrograde cholangiopancreatography (ERCP) serves as the definitive diagnostic and classification tool. Upon confirmation of diagnosis, patients should undergo curative surgery to mitigate the risk of biliary tract carcinogenesis. This article provides a detailed protocol for the diagnostic and therapeutic approaches to PBM.