What labs should be drawn prior to biopsy in a suspected adrenal cortical carcinoma?

Required Laboratory Tests Before Biopsy of Suspected Adrenocortical Carcinoma

Biopsies of suspected adrenocortical carcinoma (ACC) should be avoided as they are usually not informative, potentially harmful, and do not affect patient outcomes. 1

Why Avoid Biopsy for Suspected ACC

Before discussing required labs, it's critical to understand that the ESMO-EURACAN clinical practice guidelines explicitly state that biopsies of suspected ACC are usually not informative and should be avoided 1. Research shows that transcutaneous adrenal biopsy:

• Has a maximum sensitivity of only 70% for diagnosing ACC 2
• Is associated with complications in at least 11% of patients, mainly bleeding 2
• Does not affect recurrence-free or overall survival 2

Required Laboratory Tests for Suspected ACC

If clinical circumstances absolutely necessitate a biopsy, the following comprehensive endocrine work-up should be completed first:

1. Glucocorticoid Excess Evaluation

• 1-mg overnight dexamethasone suppression test (primary screening test) 1, 3
• Free cortisol in 24-hour urine (if clinical signs of Cushing's or abnormal dexamethasone test) 1
• Basal ACTH (plasma) 1

2. Sex Steroids and Steroid Precursors Evaluation

• DHEA-S (dehydroepiandrosterone sulfate) 1, 3
• 17-OH progesterone 1
• Androstenedione 1
• Testosterone (only in women) 1
• 17-beta-estradiol (only in men and postmenopausal women) 1
• 11-deoxycortisol (if available) 1

3. Mineralocorticoid Excess Evaluation

• Serum potassium 1
• Aldosterone/renin ratio (for patients with hypertension and/or hypokalemia) 1, 3

4. Catecholamine Excess Evaluation (to rule out pheochromocytoma)

• Plasma free metanephrines or 24-hour urinary fractionated metanephrines 1, 3

Critical Importance of Ruling Out Pheochromocytoma

It is absolutely essential to rule out pheochromocytoma before any invasive procedure, as:

• Biopsy of pheochromocytomas is dangerous due to risk of provoking a hypertensive crisis 4
• Biopsies of suspected pheochromocytoma are contraindicated in most circumstances 1

Imaging Before Considering Biopsy

Before even considering a biopsy, comprehensive imaging should be performed:

• CT or MRI of abdomen and pelvis 1, 3
• Chest CT 1
• Consider FDG-PET/CT for suspected metastatic disease 1, 3

Algorithm for Suspected Adrenal Mass Management

1. Complete comprehensive hormonal evaluation as outlined above
2. Perform appropriate imaging studies
3. Discuss in multidisciplinary expert team meeting 1
4. For masses >4 cm with inhomogeneous appearance or HU >20, or all masses >6 cm, proceed directly to surgical resection rather than biopsy 3
5. Consider direct surgical resection by experienced adrenal surgeon for suspected ACC 1, 5

Conclusion

The most important consideration when approaching a suspected ACC is that biopsy should generally be avoided in favor of proper hormonal evaluation and definitive surgical management by experienced surgeons. If biopsy is absolutely necessary, a complete hormonal evaluation must be performed first, with particular attention to ruling out pheochromocytoma.