An autopsy case of immune-related severe colitis due to long-term use of nivolumab in a patient with non-small cell lung cancer.

Immune checkpoint inhibitors (ICIs) have been developed as cornerstones of cancer therapy, but the growing use of ICIs has induced immune-related adverse effects (irAEs). Immune-related colitis, which is one of the most common irAEs, generally occurs 2-4 months after ICI treatment initiation and can be life threatening. Therefore, early diagnosis and appropriate management are required.