A 54-year-old African American woman presented with complaints of headache, blurred vision, and progressive bilateral leg swelling for the past week. This was her 4th visit to the hospital in 4 months with similar complaints. Medical history was significant for 10 years of refractory hypertension, many no-show visits, consequent chronic kidney disease stage IV, on a 5 drug anti-hypertensive regimen. Admission blood pressure (BP) was 248/164 mmHg. Physical exam was significant for bilateral papilledema and lower extremity edema. Labs demonstrated acute deterioration in her renal function with creatinine 6.8 mg/dL (increased from baseline 3.3 mg/dL) and hypokalemia (3.0 mEq/L). The patient was admitted to the ICU for management of hypertensive emergency, with initiation of nitroglycerin drip and improved BP. Once stabilized and normokalemic, work-up demonstrated elevated plasma aldosterone, suppressed plasma renin activity, and an aldosterone-to-renin ratio of 48.8 ng/dl per ng/(ml·h). Workup for pheochromocytoma was negative. Renal artery ultrasound revealed no stenosis. CT abdomen reported thickening of the left adrenal gland with features suggestive of hyperplasia. The patient was transitioned to oral anti-hypertensive agents with resolution of her clinical symptoms. She was scheduled for adrenal vein sampling and possible laparoscopic left adrenalectomy.
Discussion:
Primary aldosteronism (PA) is a principal disorder of the zona glomerulosa that is characterized by hypertension, hypokalemia, increased plasma aldosterone, and suppressed plasma renin activity. Actual prevalence of PA is reported in 5 to 15% of the hypertensive population. The eponymous Conn’s syndrome, which described aldosterone-producing adenomas (APA), is the most common subtype, implicated in 50-70% of cases of PA; bilateral adrenal hyperplasia accounts for 30%. Unilateral adrenal hyperplasia (UAH) however, is a rare cause of PA accounting for less than 1% of cases. Though hyperplastic on imaging, histopathology of UAH has demonstrated adenomatous changes, and is managed as an adenoma. Early recognition is crucial to prevent permanent long-term sequelae, as management is distinctly different for adenomas versus bilateral hyperplasia. Laparoscopic adrenalectomy is indicated for both APA and UAH, resulting in normalization of BP and resolution of hypokalemia in as few as 2 years post-procedure. Bilateral adrenal hyperplasia is managed medically.
Conclusions:
This interesting case of long-standing uncontrolled hypertension with eventual discovery of UAH during admission highlights that secondary causes of long-standing refractory hypertension should not be overlooked. Early recognition of secondary hypertension would better direct more conclusive management, thereby averting irreversible end-organ damage. Though rare, the differential of UAH and similar pathologies should be considered in patients with long-standing hypertension, with early coordination of care with endocrinology by the hospitalist service.