Fulminant type 1 diabetes mellitus induced by pembrolizumab in a patient with urothelial carcinoma: A case report.

A case of fulminant type 1 diabetes mellitus secondary to administration of pembrolizumab in a patient with urothelial carcinoma is presented. Eight days after the third infusion of pembrolizumab, the patient presented with complaints of malaise and anorexia. The patient's laboratory data showed a blood glucose level of 1092mg/dl with ketonuria and negative for glutamic acid decarboxylase antibody. As leaving ketoacidosis by insulin therapy, pembrolizumab therapy was continued without delay. After administration of another eight infusions of pembrolizumab, the patient's disease was stable without new severe side effects.