What labs should be obtained to evaluate an adrenal mass?

From the Guidelines

To evaluate an adrenal mass, initial laboratory evaluation should include plasma free metanephrines or 24-hour urinary metanephrines and catecholamines to rule out pheochromocytoma; 1mg overnight dexamethasone suppression test or late-night salivary cortisol to assess for Cushing's syndrome; and plasma aldosterone concentration to plasma renin activity ratio to screen for primary aldosteronism, as recommended by the most recent guidelines 1.

Key Laboratory Tests

• Plasma free metanephrines or 24-hour urinary metanephrines and catecholamines to rule out pheochromocytoma
• 1mg overnight dexamethasone suppression test or late-night salivary cortisol to assess for Cushing's syndrome
• Plasma aldosterone concentration to plasma renin activity ratio to screen for primary aldosteronism
• Serum potassium for patients with hypertension
• Dehydroepiandrosterone sulfate (DHEAS) and testosterone levels for women with signs of androgen excess
• Estradiol levels for men with feminizing symptoms

Rationale

These tests are essential because even radiographically benign-appearing adrenal masses can secrete hormones that cause significant health problems, as noted in the guidelines 1. Hormone-producing tumors require specific management approaches, while non-functional masses may need follow-up imaging or consideration for removal based on size and imaging characteristics. Testing should be completed prior to any surgical intervention as the results will guide appropriate perioperative management, particularly for pheochromocytomas which require alpha-blockade before surgery to prevent hypertensive crisis. The most recent guidelines 1 emphasize the importance of a multidisciplinary approach and shared decision-making between patients and clinicians for the management of indeterminate non-functional adrenal lesions.

From the Research

Evaluation of Adrenal Mass

To evaluate an adrenal mass, several laboratory tests are recommended to assess for hormonal excess and malignant potential. The following labs should be obtained:

• Blood tests for:
  • Electrolyte panel to evaluate for hyperaldosteronism 2
  • Adrenocorticotropic hormone (ACTH) level to evaluate for Cushing's syndrome 3, 4
  • Dehydroepiandrosterone sulfate (DHEAS) level to evaluate for adrenal hormone excess 3
  • Aldosterone-renin ratio to evaluate for primary aldosteronism 2
• Urine tests for:
  • 24-hour urinary free cortisol (UFC) excretion to evaluate for Cushing's syndrome 2
  • Urinary metanephrines and normetanephrines to evaluate for pheochromocytoma 2
• Additional tests:
  • Low-dose dexamethasone suppression test to evaluate for Cushing's syndrome 4, 2, 5
  • Late evening salivary cortisol to evaluate for Cushing's syndrome 2

Biochemical Testing

Biochemical testing is essential to identify hormonally active lesions and to rule out malignancy. The tests mentioned above should be used to evaluate for the following conditions:

• Primary aldosteronism
• Cushing's syndrome
• Pheochromocytoma
• Subclinical Cushing's syndrome 4, 5

Clinical Assessment

A clinical assessment should also be performed to evaluate for signs and symptoms of hormonal excess, such as hypertension, hypokalemia, and cushingoid features. This assessment, combined with imaging characteristics and biochemical testing, will help to determine the appropriate course of action for the patient 3, 6