Hypophysitis from immune checkpoint inhibitors: challenges in diagnosis and management

This review will summarize the most recent and pertinent evidence regarding immune checkpoint inhibitor (ICI)-induced hypophysitis to describe diagnostic and management algorithm with the help of a case report.

Hypophysitis is the most common endocrine adverse event from CTLA-4 inhibitors and much less with PD-1/PD-L1 inhibitors. Its pathophysiology appears to be lymphocytic, predominantly affecting the anterior pituitary. The utility of high-dose glucocorticoids for treatment has been questioned, as they do not influence recovery of hypopituitarism and may reduce survival. A survival benefit with hypophysitis has been suggested.

The nonspecific nature of symptoms underlies the importance of clinical and hormonal monitoring especially in the first 6 months of CTLA-4 inhibitor cancer therapy. Adrenal insufficiency can be a diagnostic and management challenge, which persists in most cases; hence, a multidisciplinary team of oncologists and endocrinologists is essential for providing high-quality care to these patients. High-dose glucocorticoids should be reserved for mass effect or optic chiasm impingement. The ICI may need to be temporarily withheld but not discontinued. A survival advantage in cancer patients that develop ICI-induced hypophysitis may be a silver lining, especially as ICIs are being investigated for advanced endocrine malignancies.