Abstract
Background. Immune-checkpoint inhibitors (ICIs) are associated with various immune-related adverse events (irAEs). We report a case of a patient undergoing ICI therapy who developed grade IV hepatobiliary dysfunction that was initially suspected to be an irAE, which temporarily improved with corticosteroid therapy but which was later determined to be unrelated to irAEs. Case. A 77-year-old male smoker with squamous cell lung cancer (unresectable and difficult to treat with definitive radiation therapy) was treated with pembrolizumab. After 15 cycles, he presented to the emergency department with chest discomfort, accompanied by grade IV liver dysfunction and unstable angina. Liver dysfunction was presumed to be caused by an irAE without a histological diagnosis. Corticosteroid therapy resulted in a dramatic improvement of the liver function. The patient underwent percutaneous coronary intervention, and was given three antiplatelet drugs, including one previously administered drug, which made it difficult to perform a liver biopsy. During immunosuppressive treatment, the patient developed a cholestatic pattern of liver injury. Various precision examinations were performed. He was diagnosed cholangiocarcinoma based on the results of various detailed examinations, and histopathological findings confirmed the absence of irAEs. Conclusion. Corticosteroids can transiently improve symptoms caused by metastasis, infections, or secondary malignancies. In smokers with lung cancer, the possibility of multiple primary cancers must be considered. Even if symptoms improve temporarily with steroid therapy, caution is needed before attributing symptoms to irAEs during ICI treatment.
