A case of secondary adrenocortical insufficiency due to isolated adrenocorticotropic hormone deficiency with empty sella syndrome after pembrolizumab treatment in a patient with metastatic renal pelvic cancer.

Pembrolizumab, an anti-programmed death-1 specific monoclonal antibody is a second-line treatment for metastatic urothelial carcinoma. Physicians should be aware of adverse immune-related events associated with the use of immune checkpoint inhibitors, particularly adrenocortical insufficiency, which poses a risk of death. We report a case of secondary adrenocortical insufficiency due to isolated adrenocorticotropic hormone deficiency with empty sella syndrome after pembrolizumab treatment in a patient with metastatic renal pelvic cancer. Fortunately, a therapeutic effect was observed 4 months after discontinuation of pembrolizumab, and a durable antitumor response has persisted for 5 months.