SAT-471 Management Challenges in Bilateral Adrenal Adenomas with Aldosterone-Cortisol Co-secretion

Abstract Disclosure: H.A. Mejia: None. Z.C. Hannoush: None. A. Razzeto: None. Management Challenges in Bilateral Adrenal Adenomas with Aldosterone-Cortisol Co-secretion.Bilateral incidental adrenal nodules account for 10–23% of all incidental adrenal nodules. While their management is generally similar to unilateral nodules, there are key differences in diagnosis and treatment. 75% of bilateral nodules are benign, nonfunctioning adenomas, but they are more likely to cause hormonal overproduction than unilateral nodules. Common endocrine conditions linked to these nodules include Mild Autonomous Cortisol Secretion (MACS), Cushing's syndrome, hyperaldosteronism, and congenital adrenal hyperplasia (CAH).Case descriptionA 70-year-old man with medical history of type 2 diabetes mellitus, chronic kidney disease, dyslipidemia and hypertension, presented with bilateral adrenal incidentalomas of 1.8 cm (-6 Hounsfield units) on the right and 1.6 cm (-18 Hounsfield units) on the left. Physical examination revealed BP 174/81 mmHg, HR 80 bpm, BMI 31, no purple striae, proximal muscle weakness, or bruising. Laboratory workup showed a GFR of 19 mL/min/1.73m2, K of 5.0 mmol/L (reference 3.5-5.3 mmol/L) , AM serum cortisol of 13 mcg/dL (reference: 6.2-19.4 mcg/dL) and ACTH13 pg/mL (6 - 50 pg/mL) , an elevated aldosterone 34 ng/dL (Reference 0.0 - 30.0 ng/dL) and a renin of 0.14 ng/mL/h (Reference 0.25 - 5.82 ng/mL/h) Cortisol after a 1 mg dexamethasone suppression test was 7.7 mcg/dL, and a salivary cortisol at 11 pm was 0.06, along with a 24-hour urine cortisol of 30 mcg/24 h (Reference 4.0 - 50.0 mcg/24 h). These results indicated the presence of hyperaldosteronism and a secondary diagnosis of MACS.Arterial venous sampling (AVS) revealed no lateralization of aldosterone secretion, Eplerenone was added to the patient’s antihypertensive medications (Amlodipine, lisinopril, chlorthalidone and Carvedilol) with significant improvements in blood pressure control. Subsequently, due to difficulties associated with managing his diabetes mellitus, Mifepristone was added to his medical regimen to address his hypercortisolism.Discussion: Co-secreting adrenal adenomas, though rare, should be considered during the initial workup, as up to 21% of primary aldosteronism patients have excess glucocorticoids, which if not properly managed can cause increased mobility. These adenomas are typically unilateral but can involve multiple tumors. AVS can differentiate unilateral vs bilateral hyperaldosteronism, but its interpretation is challenging when there is cortisol co-secretion. Bilateral co-secreting adrenal adenomas are exceedingly rare with no established incidence in the literature. This case highlights the diagnostic and management complexities in such patients, emphasizing the importance of individualized therapeutic approaches. Presentation: Saturday, July 12, 2025