What hormonal tests are recommended for an incidental adrenal mass?

Hormonal Testing for Incidental Adrenal Mass

All patients with adrenal incidentalomas should undergo comprehensive hormonal screening, including tests for cortisol excess, pheochromocytoma, and primary aldosteronism in hypertensive or hypokalemic patients. 1

Required Hormonal Tests for All Patients

• 1-mg Overnight Dexamethasone Suppression Test

  • Mandatory for all patients to detect cortisol excess
  • Screens for autonomous cortisol secretion which may be present in up to 30-50% of incidentalomas 2
  • Failure to detect subclinical Cushing's syndrome can impact perioperative management

• Plasma or 24-hour Urinary Metanephrines

  • Required for all patients to rule out pheochromocytoma
  • Critical safety measure as failure to identify pheochromocytoma before any intervention can cause life-threatening crisis 1
  • Particularly important before surgical resection

Selective Hormonal Tests Based on Clinical Presentation

• Aldosterone-to-Renin Ratio

  • Indicated for patients with:
    • Hypertension
    • Unexplained hypokalemia
  • Screens for primary aldosteronism (aldosterone-secreting adenoma)

• Sex Hormones and Steroid Precursors

  • Indicated when adrenocortical carcinoma is suspected based on:
    • Mass >4 cm
    • Irregular margins or heterogeneous appearance on imaging
    • Signs of virilization (females) or feminization (males)
  • Tests include DHEAS, androstenedione, testosterone, estradiol

Algorithmic Approach to Hormonal Testing

1. Initial Evaluation:

   • 1-mg overnight dexamethasone suppression test
   • Plasma free or 24-hour urinary fractionated metanephrines
   • Blood pressure measurement and serum potassium level

2. If Hypertension or Hypokalemia Present:

   • Add aldosterone-to-renin ratio

3. If Imaging Suggests Possible Malignancy (>4 cm, irregular margins, heterogeneity, >10 HU):

   • Add sex hormones and steroid precursors

Follow-up Hormonal Evaluation

• For non-functional masses with benign radiological characteristics:
  • Annual hormonal follow-up for 4-5 years to detect potential development of hormonal hypersecretion 1
  • Focus on dexamethasone suppression test and metanephrines
  • More frequent monitoring for masses ≥3 cm

Important Considerations

• Hormonal evaluation must be completed before any surgical intervention
• False-positive results may occur with certain medications or conditions
• Interpretation should consider the patient's clinical context
• Multidisciplinary review involving endocrinologists, surgeons, and radiologists is recommended when:
  • Imaging is not consistent with a benign lesion
  • There is evidence of hormone hypersecretion
  • The tumor has grown significantly during follow-up
  • Adrenal surgery is being considered 3

Pitfalls to Avoid

• Failing to screen for pheochromocytoma before any intervention (including biopsy)
• Overlooking mild autonomous cortisol secretion which can impact perioperative management
• Performing needle biopsy of potentially resectable adrenal masses (contraindicated)
• Delaying surgical management of suspected adrenocortical carcinoma
• Neglecting hormonal follow-up for seemingly benign masses

By following this comprehensive hormonal testing approach, clinicians can effectively identify functional adrenal tumors that require intervention, thereby reducing morbidity and mortality associated with undiagnosed hormonal excess syndromes.