Concomitant Pheochromocytoma and Primary Aldosteronism: A Case Series and Literature Review

Context: The detection and management of concomitant pheochromocytoma (PHEO) and primary aldosteronism (PA) is not well understood. Objective: To investigate varying presentations and outcomes of cases with coexisting PHEO and PA to provide an approach to its diagnosis and management. Methods: We conducted a retrospective case series of adult patients with concomitant PHEO and PA at Mayo Clinic from 2000-2020 and an additional review of cases before 2000 and from the medical literature. Clinical, biochemical, radiologic, and histologic parameters were measured. Results: Fifteen patients (53% men, median age 53 years) were diagnosed with concomitant PHEO and PA. The majority presented with hypertension (13, 87%) and hypokalemia (13, 87%), and 6 (40%) presented with symptoms suggestive of catecholamine excess. All patients who underwent preoperative workup for catecholamine excess (14, 93%) were found to have biochemical levels above the upper limits of normal. Adrenal vein sampling (AVS) was performed in 9 patients (60%), where 5 (56%) were diagnosed with bilateral PA, and 4 (44%) with unilateral PA. Patients underwent either unilateral (12, 80%) or bilateral (3, 20%) adrenalectomy. Biochemical improvement or resolution of catecholamine excess was confirmed in all cases with documented measurements. Recurrence of PHEO was not observed. Six patients (40%) displayed persistent PA postoperatively. Conclusion: Concomitant PHEO and PA is a rare but likely underreported condition. Hypertension with or without hypokalemia should prompt evaluation for PA, while any indeterminate adrenal mass should be assessed for PHEO. Coexisting disease warrants consideration of AVS to determine the laterality of PA to ensure appropriate management.