Review Question - QID 104337

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Primary Hyperaldosteronism Studies Labs QID: 104337 (M2.EC.15.12)

QID 104337 (Type "104337" in App Search)

A 44-year-old female presents to her primary care physician with complaints of headache, fatigue, muscle weakness, and frequent urination. These issues have developed and worsened over the past month. She has no significant prior medical or surgical history other than cholecystitis managed with cholecystectomy 5 years ago. Her vital signs at today's visit are as follows: T 37.1 C, HR 77, BP 158/98, RR 12, and SpO2 99%. Physical examination is significant for tetany, mild abdominal distension, reduced bowel sounds, and hypertensive retinal changes on fundoscopic exam. The physician orders a laboratory and imaging work-up based on his suspected diagnosis. An abdominal CT scan shows an 8 cm unilateral left adrenal mass suggestive of an adrenal adenoma. Which of the following sets of laboratory findings would be most likely in this patient?

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Metabolic acidosis, hypernatremia, hyperkalemia

0/25

Metabolic acidosis, hyponatremia, hyperkalemia

2/25

Metabolic acidosis, hypernatremia, hypokalemia

12%

3/25

Metabolic alkalosis, hypernatremia, hyperkalemia

1/25

Metabolic alkalosis, hypernatremia, hypokalemia

72%

18/25

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This patient's presentation of hypertension, muscle weakness and tetany (symptoms of hypokalemia), and a unilateral adrenal mass on imaging is suggestive of a diagnosis of primary hyperaldosteronism (Conn's syndrome). Primary hyperaldosteronism is characterized by laboratory findings of increased 24-hour urine aldosterone, decreased plasma renin, metabolic alkalosis, hypernatremia, and hypokalemia.

Seventy percent of primary hyperaldosteronism is caused by a unilateral adrenal adenoma (Conn's syndrome), and the remaining 30% is due to bilateral adrenal hyperplasia of the zona glomerulosa. The condition most commonly presents in females ages 30-50. Primary hyperaldosteronism is one of the most common causes of secondary hypertension; it is due to increased plasma volume as a result of increased sodium reabsorption. Presentation includes hypertension, headaches, tetany and muscle weakness (signs of hypokalemia). Management of this condition includes beta blockers and/or diuretics for hypertension, adrenalectomy for Conn's syndrome, or spironolactone for bilateral adrenal hyperplasia.

Higgins et al. discuss evaluation and work-up after detection of an adrenal mass. Twenty-four hour urinary free cortisol measurement can rule in/out Cushing's syndrome. To test for pheochromocytoma, twenty-four hour urinary metanephrines, vanillylmandelic acid, and/or catecholamines are necessary. A serum potassium level is helpful to confirm or rule out a diagnosis of hyperaldosteronism.

Muth et al. conducted a systematic review of management strategies for primary hyperaldosteronism. In comparing surgical (partial or total adrenalectomy) to medical management, surgery was associated with fewer antihypertensive medications after surgery, better quality of life scores, and lower all-cause mortality. Partial adrenalectomy may be a better option than total adrenalectomy for some patients, except in cases of multiple adenomas or adenoma(s) in combination with adrenal hyperplasia.

Illustration A explains the pathophysiology of primary hyperaldosteronism. Illustration B shows a coronal abdominal CT scan of a patient with a right adrenal adenoma (arrow).

Incorrect Answers:
Answers 1-4: Primary hyperaldosteronism (Conn's syndrome) is characterized by increased aldosterone, decreased renin, metabolic alkalosis, hypernatremia, and hypokalemia.

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