FRI344 Is It Possible To Have Two Endocrinopathies From Checkpoint Inhibitor Therapy At The Same Time?

Disclosure: A.N. Davis: None. G. Elshimy: None. Introduction: Checkpoint inhibitor (CPI) therapy with ipilimumab and nivolumab has become commonly used in patients with metastatic melanoma. Endocrinopathies, including hypophysitis and thyroiditis, have been reported as adverse effects. These endocrinopathies may occur with ipilimumab alone, but the incidence increases in combination therapy. Most of the cases present with one endocrinopathy at a time. We present a case highlighting the possibility of two endocrinopathies presenting simultaneously in patients treated with ipilimumab and nivolumab. Case: A 69-year-old female with stage IV choroidal melanoma presented to the ED on 7/12/22 with a sudden new onset headache for one week. CT head without contrast was unremarkable, and she was discharged home. She had been started on combination CPI therapy with ipilimumab and nivolumab on 5/26/2022, and her last dose was on 7/30/2022. An MRI brain with and without contrast was obtained by her Hematology-Oncology provider for worsening headaches on 8/15/2022 which revealed an eccentric left sellar hypo-enhancing mass that was not seen on the previous MRI brain performed on 5/24/2022. On 8/31/2022, the patient returned back to the ED with complaints of fever, weakness, altered mentation, and diarrhea. She was noted to be febrile and tachycardic with hypotension refractory to intravenous fluids. She was transferred to the medical ICU and started on a norepinephrine drip. Prior to the initiation of norepinephrine, her cortisol level was 2.40 mcg/dL with ACTH level of <5.0 pg/mL. The remainder of labs were significant for TSH <0.010 mcIU/mL, free T4 3.26 (0.58-1.76ng/dL), free T3 4.59 (2.30-4.20 pg/mL), LH 1.27 (15.9-54.0 mIU/mL), FSH 12.76 (23.0-116.3 mIU/mL), prolactin 0.56 (1.8-20.3 ng/mL), TSI <1.0 (<1.3), TRAb <1.10 (<1.75 IU/L), TPO Ab 0.5 (<9.0 IU/mL). Labs were consistent with hypopituitarism and thyrotoxicosis. She was started on stress dose hydrocortisone which was weaned to a PO maintenance dose prior to discharge. An MRI brain pituitary protocol was obtained on 9/5/2022 which revealed the same hypoattenuating sellar lesion which was slightly smaller than on the previous MRI. The patient’s presentation was attributed to pituitary apoplexy in the setting of preceding hypophysitis as well as thyroiditis. Her hypophysitis and thyroiditis were attributed to her treatment with ipilimumab and nivolumab. On 11/22/2022, free T3 was 1.83 pg/mL, free T4 was <0.25 ng/dL, and TSH was 2.538 mcIU/mL, consistent with resolved thyroiditis but developing central hypothyroidism. Discussion: CPI therapy is associated with the development of endocrinopathies including thyroiditis and hypophysitis. Our case demonstrates that it is possible for multiple endocrinopathies to present simultaneously in the setting of CPI therapy and that delay in diagnosis can precipitate adrenal crises. Given the frequency with which endocrinopathies can occur with CPI therapy, appropriate screening and follow-up are recommended in order to provide prompt diagnosis and management of these patients. Presentation: Friday, June 16, 2023