FRI332 Check Point Inhibitor Induced Hypophysitis/Hypopituitarism

Disclosure: R.S. Chandpuri: None. Introduction: A case of Renal cell cancer with metastasis to contralateral kidney, which was treated with nivolumab/ Ipilimumab leading to hypophysitis/hypopituitarism. Case: 42-year-old female with past medical history of Left renal mass who underwent left radical nephrectomy. On surveillance imaging she was found to have evidence of new paraspinal mass suspicious for metastatic spread involving retroperitoneal lymph nodes and contralateral kidney. She would be referred to her oncologist for observation versus chemotherapy. Her oncologist ordered nivolumab and ipilimumab. Patient tolerated chemotherapy well. A surveillance brain MRI was ordered to check for any metastatic involvement and it showed enlargement of the pituitary gland with focal hypo-enhancing area concerning for immune check point inhibitor therapy induced hypophysitis. Labs showed- cortisol-0.8, ACTH <5, TSH-0.6, Free T4-0.60, Prolactin-57.9, FSH-3.7, LH-5.0. Clinically she would complain of fatigue, generalized weakness, hypotension and amenorrhea. The patient was reluctant to start thyroid hormone replacement therapy, and she appeared clinically euthyroid. A dedicated Pituitary MRI showed partially empty sella turcica, sella measuring approximately 0.2 cm in maximal height. There was no abnormal thickening or nodular enhancement of the pituitary stalk. No suprasellar mass effect or chiasmatic compression. She was placed on Prednisone/ Hydrocortisone with improvement in her fatigue and blood pressure. Conclusion: Immune checkpoint inhibitors are a new form of immunotherapy used in the treatment of various cancers (melanoma, RCC, colorectal). These agents can cause immune-mediated pituitary lesions (hypopituitarism/hypothyroidism). These drugs can cause a spectrum of issues ranging from single hormone deficiency to pan-hypopituitarism. Due to the new advances in chemo/immune therapy, providers need to be aware of such conditions to quickly recognize and treat them. Symptoms of this condition can be masked and can be attributed to other diseases processes ie(depression, anxiety, chronic fatigue syndrome). It would be best to come up with a screening process/order set for such patients with close communication between primary care, endocrinologists, oncologists in order to identify and treat the patients. Presentation: Friday, June 16, 2023