Atezolizumab-induced Sclerosing Cholangitis in a patient with lung cancer: A case report

Atezolizumab is an immune checkpoint inhibitor that is a key drug in non-small-cell lung cancer treatment. However, it can cause immune-related adverse events, including liver injury. Several patterns of liver injury associated with immune checkpoint inhibitor therapy have been reported; however, not much is known about sclerosing cholangitis. We present here a case of lung adenocarcinoma with atezolizumab-induced secondary sclerosing cholangitis diagnosed using needle biopsy of the liver. A 77-year-old woman with lung adenocarcinoma, cT3N2M0, stage IIIA, was treated with concurrent chemoradiotherapy involving carboplatin and paclitaxel, which markedly reduced the tumor diameter. However, 5 months later, the lesion regrew, and she underwent 39 cycles of pemetrexed monotherapy. As pulmonary metastasis progressed, she was treated with atezolizumab. After 13 cycles of atezolizumab therapy, she complained of nausea. Laboratory tests showed elevated levels of the biliary tract and hepatic enzymes. Nevertheless, abdominal computed tomography and ultrasonography revealed no underlying related cause. Ultrasound-guided needle biopsy of the liver was performed, and histopathological analysis of biopsy samples showed features of sclerosing cholangitis. Further examinations were performed, and a diagnosis of atezolizumab-induced secondary sclerosing cholangitis without strictures and dilatations of the large bile ducts was established. Prednisolone was administered orally, after which the biliary tract and hepatic enzyme levels improved immediately. In patients presenting with a hepatic injury during immune checkpoint inhibitor therapy, clinicians should be aware of the possibility of immune checkpoint inhibitor-induced sclerosing cholangitis, even if the large bile ducts have no strictures and dilatations.