Immunoglobulin (Ig) G4-related sclerosing cholangitis in patients resected for presumed perihilar cholangiocarcinoma: a 10-year experience

BACKGROUND: This study aimed to investigate the incidence of immunoglobulin (Ig) G4-related sclerosing cholangitis (IgG4-SC) in patients resected for perihilar cholangiocarcinoma (PHC) in a designated hospital from 2010 to 2019. We also aimed to evaluate the diagnostic dilemma of IgG4-SC clinically. METHODS: Between January 2010 and December 2019, all patients who underwent radical resection due to presumed PHC were included. Independent pathologists scored bile duct samples based on the International Consensus Pathology Criteria for IgG4-related Disease (ICPD). RESULTS: Of the 289 patients who underwent radical resection of primary liver cancer, 26 (9%) were diagnosed as benign, without histological evidence of malignancy, among them, 23 had sclerosing inflammation, 1 had cystadenoma, and 2 had xanthogranulomatous cholangitis. Additionally, 18 had a definitive diagnosis of IgG4-SC. The misdiagnosis rate was 19% (54/289), of which, 26 patients had benign disease, and 28 patients had malignancies. CONCLUSIONS: It is difficult to distinguish IgG-SC from PHC. The misdiagnosis has resulted in a large number of ineffective hepatectomies. Improving the detection rate of serum IgG4 (sIgG4) may therefore avoid misdiagnosis, surgery, and life-threatening complications.