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.