SUN-502 Unmasking Pheochromocytoma, A Rare Case of DKA as the First Clue

Abstract Disclosure: D. Saba: None. L. Li: None. M.M. Khan: None. J.A. Vu: None. Background: Pheochromocytomas are rare catecholamine-secreting tumors of the adrenal medulla, typically associated with episodic or sustained hypertension, headaches, palpitations, and sweating. These tumors can cause mild hyperglycemia through increased insulin resistance and glucagon secretion; however, the development of DKA as the initial presentation is exceedingly rare. This case underscores the diagnostic challenges and clinical implications of this atypical presentation.Clinical Case: A 62-year-old woman presenting with nausea, vomiting, polyuria, and polydipsia. She admitted to the hospital with DKA, new-onset DM and hypertensive urgency. Incidentally discovered bilateral adrenal masses on abdominal imaging prompted further evaluation. A 6.6 cm hemorrhagic right adrenal mass and a 2.6 cm lipid-rich left adrenal lesion were identified. Subsequent biochemical workup confirmed pheochromocytoma with markedly elevated plasma and urine metanephrines (>10 times the upper limit of normal). This case highlights a rare presentation of pheochromocytoma with DKA, demonstrating the complex interplay of catecholamines in glucose metabolism.This patient presented without these hallmark symptoms of pheochromocytoma. Her presentation included refractory insulin requirements and severe hypertension, which strongly suggested catecholamine excess. Elevated catecholamine levels from the tumor inhibited insulin secretion, promoted lipolysis, and increased gluconeogenesis. While DKA is rarely associated with pheochromocytoma, its presence in this case underscores the metabolic disruptions caused by excess catecholamines. Definitive treatment involved surgical removal of the tumor, which resolved the patient’s hyperglycemia and minimized antihypertensive requirements.Lessons: It is essential for clinicians to maintain a high index of suspicion for secondary causes of DKA when typical risk factors are absent or when adrenal pathology is detected incidentally. Early identification and surgical intervention are critical to mitigate the life-threatening complications associated with this rare endocrine tumor. References:1. Lenders JWM, Eisenhofer G, Mannelli M, Pacak K. Phaeochromocytoma. Lancet. 2005;366(9486):665-675. doi:10.1016/S0140-6736(05)67139-52. Sedhai YR, Reddy K, Patel D, et al. Unusual case of pheochromocytoma presenting with diabetic ketoacidosis. Case Reports: 2016;2016:bcr2016216961. doi:10.1136/bcr-2016-2169613. Hedley JS, Law S, Phookan S, Lee MN, Ioachimescu A, Levit RD. Pheochromocytoma masquerading as "diabetic ketoacidosis." J Investig Med High Impact Case Rep. 2016;4(2):2324709616646128. doi:10.1177/2324709616646128 1 Presentation: Sunday, July 13, 2025