FRI226 Ectopic Cushing’s Syndrome Of Unknown Primary Origin With Etomidate Use

Abstract

Abstract Disclosure: C. Ohammah: None. J. Lloyd: None. T. Abdulwahid: None. R. Tangri: None. C. Musgrove: None. K. Selk: None. Background: Ectopic Cushing's syndrome (ECS) is rare and requires adrenolytic agents to control hypercortisolism until a definitive plan can be made to treat the underlying cause. We present a case of ECS of unknown primary origin causing immunosuppression due to the hypercortisolism that responded with etomidate infusion. Case: A 61-year-old male who presented to the hospital after a few weeks of increasing weakness, dyspnea, and hemoptysis. In the months prior to his admission, he was found to have persistent hypokalemia, COVID pneumonia, and new onset diabetes mellitus. On admission, his examination was remarkable for proximal hip flexor weakness. Labs were significant for metabolic alkalosis, hyperglycemia (A1c 7.7%) and persistent hypokalemia requiring about 300 mEq of potassium daily. CT chest, abdomen and pelvis was remarkable for aspiration pneumonia, vertebral compression fracture, and bilateral adrenal enlargement. Blood cultures grew Staphylococcus Aureus (MSSA) (suspected lung source) and Candida albicans. Treatment with vancomycin and caspofungin was initiated and narrowed to cefazolin after speciation. His MSSA cleared rapidly however, fungemia was persistent after 1.5 weeks of treatment. MRI brain was unremarkable for causative lesion. Further testing revealed elevated morning cortisol (136.2ug/dL) confirmed on repeated testing and elevated ACTH (653pg/mL). Serum metanephrines were normal. A high-dose dexamethasone suppression was unremarkable. In the following days, he developed respiratory failure secondary to a spontaneous hemothorax requiring intubation and ICU admission. He was started on an etomidate infusion given abnormal liver enzymes and unavailability of metyrapone. The infusion was titrated every 6 hours based on cortisol levels. His liver enzymes improved and ketoconazole was added but later discontinued due to development of thrombocytopenia. His cortisol level decreased (21.5ug/dL) and fungemia cleared. Arrangement for bilateral adrenalectomy was made but the patient decompensated and developed shock requiring pressors. After a goals of care discussion, he was transitioned to comfort measures and eventually passed. Conclusion: ECS is rare, and the diagnosis is challenging and often delayed. Ectopic ACTH can result from various malignancies. Medical management with adrenolytic agents should be considered early in the management of ECS until a definitive plan is made. Etomidate, ketoconazole, metyrapone, and mitotane can be used to treat hypercortisolism to achieve medical adrenalectomy. Bilateral adrenalectomy should be considered in patients without adequate response to adrenolytic agents. This case describes the severity of hypercortisolism from an ectopic ACTH production causing refractory hypokalemia and immunosuppression resulting in fatal infections. We highlight the use of etomidate to control hypercortisolism. Presentation: Friday, June 16, 2023