Is ordering a comprehensive hormonal evaluation, including aldosterone (ALD)/plasma renin activity ratio, adrenocorticotropic hormone (ACTH), cortisol, metanephrines, dehydroepiandrosterone sulfate (DHEA-S), androstenedione, testosterone, 17-hydroxyprogesterone, and estradiol, relevant for an adrenal incidentoma with minimal growth?

Appropriate Laboratory Testing for Adrenal Incidentaloma with Minimal Growth

For an adrenal incidentaloma with minimal growth, a focused hormonal evaluation is recommended, including 1 mg overnight dexamethasone suppression test, plasma metanephrines, and aldosterone/renin ratio, but the extensive panel requested is excessive and not supported by current guidelines.

Core Recommended Testing

• 1 mg overnight dexamethasone suppression test with morning cortisol measurement is the essential first-line test for all adrenal incidentalomas to screen for autonomous cortisol secretion 1
• Plasma free metanephrines or 24-hour urinary metanephrines should be obtained to rule out pheochromocytoma, especially if the mass is ≥10 HU on non-contrast CT 1
• Aldosterone/plasma renin activity ratio should be measured only in patients with hypertension and/or hypokalemia to screen for primary aldosteronism 1

Unnecessary Tests for Minimal Growth

• DHEA sulfate, androstenedione, testosterone, 17-hydroxyprogesterone, and estradiol are not routinely recommended for adrenal incidentalomas with minimal growth unless there are specific clinical signs of virilization or feminization 1, 2
• These extensive androgen panels are primarily indicated when adrenocortical carcinoma is suspected (large tumors >4cm, irregular margins, heterogeneous appearance) rather than for stable or minimally growing lesions 3

Follow-up Testing Guidelines

• For adrenal incidentalomas with growth <3mm/year, no further imaging follow-up or functional testing is required 2
• For lesions growing 3-5mm/year, continued surveillance may be appropriate, but extensive hormonal testing is not indicated 2
• For lesions growing >5mm/year, repeat functional work-up is recommended before considering surgical intervention 2

Evidence-Based Approach

• The 2023 CUA/AUA guidelines indicate that only about 5.3% of adrenal incidentalomas are cortisol-secreting adenomas, 1% are aldosterone-secreting adenomas, and 5.1% are pheochromocytomas 2
• A 5-year prospective follow-up study showed that small lipid-rich adrenal incidentalomas (<40mm and <10 HU) did not develop hormonal hypersecretion during follow-up 4
• The risk of malignant transformation in benign-appearing adrenal lesions with minimal growth is extremely low (0-1%) 2

Important Considerations and Pitfalls

• Medications can interfere with hormone testing results, so consider holding interfering medications before testing when possible 1
• Bilateral adrenal incidentalomas warrant consideration of congenital adrenal hyperplasia with 17-hydroxyprogesterone measurement, but this is not indicated for unilateral masses with minimal growth 2
• Age and imaging characteristics are more important determinants of malignancy risk than minimal growth; young patients (<40 years) with indeterminate imaging features warrant more thorough evaluation 2

Conclusion for This Case

• For an adrenal incidentaloma with minimal growth, the appropriate testing includes:
  • 1 mg overnight dexamethasone suppression test (cortisol and ACTH) 1
  • 24-hour urinary metanephrines 1
  • Aldosterone/renin ratio (only if hypertensive or hypokalemic) 1
• The additional tests requested (DHEA sulfate, androstenedione, testosterone, 17-hydroxyprogesterone, estradiol) are excessive and not supported by current guidelines for lesions with minimal growth 2