SUN-511 Unmasking the Hidden Threat: Diagnosing Pheochromocytoma in a Patient with Resistant Hypertension and End-Stage Renal Disease on Long-Term Hemodialysis

Abstract Disclosure: S. Hossain: None. S. Marowa: None. J. Delshad: None. H. Liao: None. D. Rosenthal: None. S.C. Kumar: None. Background: Pheochromocytoma is a rare tumor that originates from the adrenal medulla, occurring in 2 to 8 cases per million people each year. It is found in 0.1 to 1% of hypertensive patients (1,2) and is even more uncommon in those with end-stage renal disease (ESRD), with only 15 reported cases to date (3). This case highlights the challenges associated with diagnosing pheochromocytoma in patients with ESRD. Case presentation: A 55 year old female with ESRD on hemodialysis (HD) presented to the hospital with abdominal pain and shortness of breath and was found to be in a state of hypertensive emergency. She had been admitted multiple times over a span of two years for hypertensive crises but denied any episodes of palpitations, pallor, sweating, or headache. Despite adherence to considerable dosage of four antihypertensive medications and her hemodialysis regimen, her blood pressure control remained subpar. An abdominal CT without contrast obtained for her abdominal pain showed a 2.3 x 2.0 cm right adrenal nodule with an intensity of 40 HU. Her free metanephrine level was 564 pg/ml (∼10 times upper limit of normal (ULN), free normetanephrine: 420 pg/ml (∼3 times ULN), epinephrine: <2x ULN, and normal dopamine, cortisol, aldosterone and renin activity. She was started on prazosin with improvement of her blood pressure. She underwent right-sided robot-assisted adrenalectomy after four weeks of alpha blockade without perioperative complications. She received dialysis the day prior to surgery and was deemed volume optimized. Surgical pathology confirmed a 5.5 cm pheochromocytoma. She was discharged on prazosin and losartan. Conclusion: Our case highlights the challenges in diagnosing pheochromocytoma in patients with ESRD on HD. These challenges arise because patients with ESRD often struggle to control their blood pressure, and traditional urine screening tests become unreliable due to anuric status. Moreover, long-term dialysis can lead to elevated catecholamine levels. Currently, no established protocols exist for screening pheochromocytoma in these patients. Therefore, it is crucial for clinicians to consider pheochromocytoma as a potential cause of resistant hypertension in patients on dialysis. Implementing a screening protocol for this population could help expedite diagnosis and prevent morbidity and mortality. Reference: 1.Beard CM, Sheps SG, Kurland LT, et al.: Occurrence of pheochromocytoma in Rochester, Minnesota, 1950 through 1979. Mayo Clin Proc 58 (12): 802-4, 1983. 2.Stenström G, Svärdsudd K: Pheochromocytoma in Sweden 1958-1981. An analysis of the National Cancer Registry Data. Acta Med Scand 220 (3): 225-32, 1986. 3.John A. Godfrey, Otis B. Rickman, Amy W. Williams, Geoffrey B. Thompson, William F. Young, Pheochromocytoma in a Patient With End-Stage Renal Disease, Mayo Clinic Proceedings, Volume 76, Issue 9, 2001, Pages 953-957, ISSN 0025-6196. Presentation: Sunday, July 13, 2025