2020 Volume 34 Issue 5 Pages 828-839
The concept "sclerosing cholangitis" includes various diseases with different clinical courses and therapeutic indications. PSC reveals inflammations and fibrosis in all the levels of the bile ducts, but liver biopsy of the lesion tissues is difficult due to a non-uniform distribution of the lesion. However, a liver biopsy is often necessary for diagnosing PSC in children. Active inflammation containing granulation tissues rich in inflammatory cells may be present in the large bile duct, and can be obtained by a bile duct biopsy. IgG4-related sclerosing cholangitis occurs in the large bile ducts, but aquisition of the lesional tissues by a bile duct biopsy is difficult because of an intramural distribution of lymphoplasmacytic infiltration and fibrosis. When the lesions occur in the intrahepatic bile ducts, inflammatory cell infiltration that extends along the portal tracts can be obtained by a liver biopsy. Among various diseases that show secondary sclerosing cholangitis (SSC), eosinophilic cholangitis, immune-related adverse events caused by immune checkpoint inhibitors, and SSC in critically ill patients are mentioned briefly in this review.
