Pancreaticobiliary maljunction and biliary cancer

Area of Science:

• Gastroenterology
• Surgical Oncology
• Diagnostic Imaging

Background:

• Pancreaticobiliary maljunction (PBM) is a congenital anomaly where pancreatic and bile ducts join outside the duodenal wall.
• This anatomical variation leads to pancreatic juice reflux into the biliary tract, increasing the risk of biliary cancer.
• Japanese guidelines for PBM management were established in 2012, with revised diagnostic criteria in 2013.

Purpose of the Study:

• To summarize the diagnostic criteria and management strategies for Pancreaticobiliary maljunction (PBM).
• To highlight the association between PBM and increased risk of biliary tract carcinogenesis.
• To discuss the challenges in managing PBM without biliary dilatation and recommend early detection methods.

Main Methods:

• Review of diagnostic modalities including direct cholangiography, magnetic resonance cholangiopancreatography (MRCP), CT, and endoscopic ultrasonography (US).
• Analysis of nationwide survey data on biliary cancer incidence in patients with and without biliary dilatation associated with PBM.
• Evaluation of pathophysiological conditions predisposing to PBM complications.

Main Results:

• Biliary cancer was detected in 21.6% of adult PBM patients with biliary dilatation and 42.4% of those without.
• Gallbladder cancer was more prevalent than bile duct cancer in both groups.
• Pathophysiological conditions include a long common channel (≥6 mm) and abnormal sphincter function.

Conclusions:

• Immediate prophylactic surgery is recommended upon PBM diagnosis.
• The surgical strategy for PBM without biliary dilatation requires further clarification.
• MRCP is recommended for early detection of PBM without biliary dilatation in patients with gallbladder wall thickening on screening US.