Pancreaticobiliary fistula associated with intraductal papillary mucinous neoplasm and the simultaneous ampullary carcinoma: A case report.

RATIONALE: Intraductal papillary mucinous neoplasms (IPMNs) may perforate into adjacent organs, but pancreaticobiliary fistula caused by IPMN is rare. We present a rare case of pancreaticobiliary fistula due to a branch-duct IPMN, accelerated by a simultaneous ampullary carcinoma.

PATIENT CONCERNS: A woman in her 70s developed obstructive jaundice and cholangitis after a year of follow-up for IPMN.

DIAGNOSES: Imaging revealed a branch-duct IPMN with a mural nodule and dilation of the main pancreatic duct, along with a dilated distal bile duct. Perforation into the bile duct and lymphadenopathy were observed. Histopathology later confirmed a high-grade intestinal-type IPMN and an incidental ampullary ductal carcinoma.

INTERVENTIONS: The patient underwent endoscopic biliary drainage followed by pancreaticoduodenectomy after improvement of cholangitis.

OUTCOMES: The postoperative course was favorable. The pancreaticobiliary fistula was attributed to mechanical compression by mucin-producing IPMN, complicated by ampullary carcinoma.

LESSONS: This case highlights the importance of recognizing synergistic effects of concurrent periampullary neoplasms. Surgical resection may be curative and necessary to control complex biliary obstruction and infection.