Secondary sclerosing cholangitis with hemobilia induced by pembrolizumab: Case report and review of published work.

A 66-year-old man was admitted to our department due to cholestatic liver injury. He had received five cycles of pembrolizumab for small-cell lung cancer. Imaging showed the possibility of sclerosing cholangitis (SC) with hemobilia. Histologically, CD8 T cells had infiltrated the biliary epithelium of the extrahepatic bile duct. We reached the diagnosis of secondary SC induced by pembrolizumab. Although we treated him with high-dose corticosteroids, laboratory data showed only a moderate response. Clinicians should recognize that immune checkpoint inhibitors can sometimes cause severe and irreversible SC.