Primary hyperaldosteronism secondary to unilateral adrenal hyperplasia: an unusual cause of surgically correctable hypertension. A review of 30 cases.

INTRODUCTION

Unilateral adrenal hyperplasia (UAH) is a rare, surgically correctable cause of primary hyperaldosteronism (PH). We report 2 cases and review the literature for cases of PH secondary to UAH successfully treated via surgery.

METHODS

Two cases of UAH treated at our institution were retrospectively reviewed. In addition, we reviewed 28 cases of UAH previously reported in the English literature.

RESULTS

Median patient age was 49 (range: 10-62) years, with a male to female ratio of 1.7:1. All patients were hypertensive, with a median preoperative systolic and diastolic blood pressure of 170 (range: 135-250) mmHg and 110 (range: 75-140) mmHg, respectively. Most patients were hypokalemic, with a median serum potassium level of 2.8 (range: 1.4-3.9) mmol/l. Ten out of 13 patients (77%) who underwent postural studies had a decrease or no change in the plasma aldosterone level, suggesting a unilateral source of hyperaldosteronism, and 9/17 patients (53%) who underwent a computed tomography (CT) scan were correctly localized. Twelve patients underwent adrenal scintigraphy with or without dexamethasone suppression, of whom 6 (50%) were correctly localized. In 1 patient, adrenal scintigraphy demonstrated localization to the opposite gland. Adrenal venous sampling (AVS) was performed in 22 patients and successfully localized the lesion in all the patients. At a median follow-up of 12 (range: 3-96) months postsurgery, 47% of patients (14/30) were completely cured of their hypertension and 50% (15/30) had improved control. All 30 patients were cured of hypokalemia.

CONCLUSION

Although the existence of UAH remains controversial, it is increasingly accepted as a unique pathologic entity and has an excellent outcome after unilateral adrenalectomy.