7305 Pheochromocytoma Presenting With Resistant Hyperglycemia

Abstract Disclosure: M. Economou: None. A. Devine: None. Background: Pheochromocytoma is a rare catecholamine producing tumor arising from the adrenal gland. Impaired glucose tolerance is a well-recognized hormonal and metabolic manifestation of pheochromocytoma caused by catecholamine excess 1. Insulin resistance requiring very high doses of insulin in association with pheochromocytoma is, however, rare. Here we report a case of pheochromocytoma in a woman with diabetes mellitus that proved difficult to control despite high-dose insulin therapy. Case presentation: A 72-year-old woman with a longstanding history of type 2 diabetes mellitus, uncontrolled hypertension, hyperlipidemia and CVA presented to the hospital after she was found to have a hemoglobin of 7.0 ng/mL on routine labs. Notably, over the past 4 years, her insulin requirement gradually increased from 20 units/day to 50 units/day despite an A1c level of 6.1%. On presentation, our patient was hypertensive to 170/90 with limited response to multiple antihypertensive medications. Additionally, her glucose was severely uncontrolled, fluctuating between 200-500 mg/dL. Within days, the patient’s total daily insulin requirement increased tremendously to as much as 300 units/day. As part of her anemia workup, she underwent a contrast-enhanced CT abdomen 11(4): e4551. Presentation: 6/3/2024