Abstract: Programmed death receptor-1 inhibitor pembrolizumab can restore the function of T cell activity and enhance the anti-tumor immune response by inhibiting the binding of PD-1 to its ligand PD-L1 and blocking the negative regulation of signal pathway. The activated T cells may cause immune-mediated adverse events in the process of anti-tumor.This article reported the severe immune related adverse effects induced by PD-1 inhibitor, pembrolizumab, in a patient with advanced ampullar carcinoma. The patient eventually died due to liver injury, leukocytosis，thrombocytopenia，and disseminated intravascular coagulation (DIC). This article reviewed the diagnosis and treatment of the patient, and reviewed the relevant literatures.

Key words: duodenal neoplasms, ampullar carcinoma, programmed death receptor-1, pembrolizumab, immune-related injury