A case of steroid-resistant cystitis as an immune-related adverse event during treatment with nivolumab for lung cancer, which was successfully treated with infliximab.

Introduction: Immune checkpoint inhibitors are widely used in various cancers as a standard treatment. However, while various immune-related adverse events related to immune checkpoint inhibitors have been reported, there are few reports of lower urinary tract symptoms.

Case Presentation: The patient was a 60-year-old man with primary lung cancer who was receiving long-term nivolumab therapy.