Gallbladder Adenocarcinoma in the Setting of Anomalous Pancreaticobiliary Junction and Type IVa Choledochal Cyst: A Case Report

Case Report: A 67-year-old female with chronic hepatitis B and cholelithiasis presented with abdominal pain and jaundice. Labs showed elevated transaminases (AST 639 U/L, ALT 724 U/L), alkaline phosphatase 201 U/L, and total bilirubin 5.5 mg/dL. MRCP revealed gallbladder wall thickening and biliary ductal dilation with common bile duct tapering, suggesting a stricture or type IV choledochal cyst. Laparoscopic cholecystectomy was performed, with histopathology confirming poorly differentiated adenocarcinoma. ERCP with EUS demonstrated an anomalous pancreaticobiliary junction (APBJ) with a 4 cm common channel and dominant pancreatic duct drainage. A mid-common bile duct stricture was found above the junction, with upstream biliary dilation consistent with type IVa choledochal cyst. The patient was referred to Medical Oncology and Hepatobiliary Surgery [1].

Discussion: APBJ, where pancreaticobiliary union occurs outside the duodenal wall, predisposes patients to biliary tract malignancies through chronic pancreaticobiliary reflux. Biliary tract cancer incidence in APBJ ranges from 21.6% to 42.4%, with higher risk when choledochal cysts are present. While MRCP is the preferred initial imaging, ERCP/EUS often provides crucial additional information. Management typically involves prophylactic surgery to reduce malignancy risk. This case highlights the carcinogenic potential of chronic biliary inflammation and stasis and emphasizes the importance of early detection and intervention in APBJ patients.

Publication History

Article published online:
27 March 2025

• References

• 1 Kamisawa T, Kuruma S, Tabata T, Chiba K, Iwasaki S, Koizumi S, Kurata M, Honda G, Itoi T.. Pancreaticobiliary maljunction and biliary cancer. J Gastroenterol 2015; 50 (3): 273-9 Epub 2014 Nov 18. PMID: 25404143