A case series of adrenal insufficiency (likely due to hypophysitis) in cancer patients treated with immune checkpoint inhibitors.

The number of approved immune checkpoint inhibitors (ICIs) and their indications have significantly increased over the past decade. Immune-related adverse effects (irAEs) of ICIs vary widely in presentation and symptoms and can present diagnostic challenges to emergency department (ED) physicians. Moreover, when ICIs are combined with radiotherapy, cytotoxic chemotherapy, or targeted therapy, the attribution of signs and symptoms to an immune-related cause is even more difficult. Here, we report a series of 5 ED cases of adrenal insufficiency in ICI-treated cancer patients. All 5 patients presented with severe fatigue and nausea. Four patients definitely had and one patient possibly had central adrenal insufficiency, and 4 patients had undetectable serum cortisol levels. The majority of the patients had nonspecific symptoms that were not recognized at their first ED presentation. These cases illustrate the need for a heightened level of suspicion for adrenal insufficiency in ICI-treated cancer patients with hypotension, nausea and/or vomiting, abdominal pain, fatigue, or hypoglycemia. As ICI use increases, irAE-associated oncologic emergencies will become more prevalent. Thus, ED physicians must update their knowledge regarding the diagnosis and management of irAEs and routinely inquire about the specific antineoplastic therapies that their ED patients with cancer are receiving. A random cortisol level (results readily available in most EDs) with interpretation taking the circadian rhythm and the current level of physiological stress into consideration can inform the differential diagnosis and whether further investigation of this potential irAE is warranted.