Single-operator cholangioscopy in the diagnosis and treatment planning of hilar intraductal papillary neoplasia of the bile duct: a case report.

A 53-year-old man presented with abdominal pain and cholestasis with normal bilirubin. Computed tomography and magnetic resonance imaging/magnetic resonance cholangiopancreatography suggested a perihilar stricture but could not exclude left-duct extension, and initial multidisciplinary review deemed the case unresectable. Endoscopic retrograde cholangiopancreatography with peroral single-operator cholangioscopy (SOC) obtained biopsy specimens, but the stricture was not traversable; repeat multidisciplinary review pursued antegrade mapping. A left percutaneous transhepatic drain was placed; 11 days after percutaneous drain placement, antegrade percutaneous SOC (pSOC) mapped right duct involvement and confirmed left hepatic duct sparing, revising resectability. The patient underwent associating liver partition and portal vein ligation for staged hepatectomy followed by extended right hepatectomy. Pathology showed intraductal papillary neoplasm of the bile duct with high-grade dysplasia and microscopically negative margins (R0); no adverse events occurred. Combined peroral and pSOC can enable curative surgery when imaging and endoscopic retrograde cholangiopancreatography are inconclusive.