부산대학교 도서관

Background and Aim: Immunoglobulin G4‐related sclerosing cholangitis (IgG4‐SC) presents as isolated proximal‐type sclerosing cholangitis (i‐SC). The present study sought to clarify the imaging differences between i‐SC and Klatskin tumor. Differences between i‐SC and IgG4‐SC associated with autoimmune pancreatitis (AIP‐SC) were also studied. Methods: Differentiating factors between i‐SC and Klatskin tumor were studied. Serum IgG4 level, CA19‐9 level, computed tomography (CT) findings, cholangiography findings (symmetrical smooth long stricture extending into the upper bile duct [SSLS]), endosonographic features (continuous symmetrical mucosal lesion to the hilar part [CSML]), endoscopic biopsy results, treatment, relapse, and survival were also compared between patients with i‐SC and those with AIP‐SC. Results: For a differential diagnosis between i‐SC (N = 9) and Klatskin tumor (N = 47), the cut‐off value of serum IgG4 level was 150 mg/dL (sensitivity, 0.857, specificity, 0.966). Logistic regression analysis indicated that serum IgG4 level, presence of SSLS, presence of CSML, and presence of swollen ampulla are independent factor for identifying i‐SC. Relapse rate was significantly higher in the IgG4‐SC with AIP group than in the i‐SC group (log rank, P = 0.046). Conclusion: Isolated proximal‐type sclerosing cholangitis presents as a nodular lesion with SSLS and/or CSML mimicking a Klatskin tumor. Those endoscopic features might provide a diagnostic clue for i‐SC. i‐SC is likely to have a more favorable prognosis than IgG4‐SC with AIP. [ABSTRACT FROM AUTHOR]