What hormone workup is recommended for a 1.5 cm left adrenal adenoma?

Hormone Workup for a 1.5 cm Left Adrenal Adenoma

All patients with adrenal incidentalomas, regardless of size, should be screened for autonomous cortisol secretion using a 1 mg overnight dexamethasone suppression test. 1

Universal Screening Required

• 1 mg dexamethasone suppression test (DST) is mandatory for all adrenal incidentalomas, taken at 11 PM with serum cortisol measured at 8 AM the following morning 1, 2
  • Cortisol ≤50 nmol/L excludes hypersecretion 1
  • Cortisol 51-138 nmol/L suggests possible autonomous cortisol secretion 1
  • Cortisol >138 nmol/L indicates cortisol hypersecretion 1

Conditional Screening Based on Clinical Features

Screen for Primary Aldosteronism IF:

• Patient has hypertension and/or hypokalemia 1, 2
• Measure aldosterone/renin ratio (ARR) in the morning after patient has been upright for 2 hours and seated for 5-15 minutes 1
• ARR >20 ng/dL per ng/mL/hr has >90% sensitivity and specificity for hyperaldosteronism 1
• Ensure patient is potassium-replete and substitute interfering medications when possible 1, 2

Screen for Pheochromocytoma IF:

• Mass measures ≥10 HU on non-contrast CT OR HU value is unavailable 1, 2
• Patient has symptoms of catecholamine excess (headaches, palpitations, sweating, anxiety attacks) 1
• Measure plasma free metanephrines or 24-hour urinary metanephrines 1, 2
• Values >2X upper limit of normal are significant 1

Important caveat: You can skip pheochromocytoma screening if the mass is unequivocally <10 HU on non-contrast CT AND the patient has no adrenergic symptoms 1

Screen for Androgen Excess IF:

• Clinical signs of virilization are present (hirsutism, acne, voice deepening, clitoromegaly, menstrual irregularities) 1, 2
• Adrenocortical carcinoma (ACC) is suspected based on imaging features (inhomogeneous, irregular margins, >4 cm) 1
• Measure DHEA-S and testosterone as initial tests 1, 2
• Extended panel if positive: 17β-estradiol, 17-OH progesterone, androstenedione, 17-OH pregnenolone, 11-deoxycorticosterone, progesterone, and estradiol 1

Critical Imaging Context

Before finalizing the hormone workup, confirm the mass characteristics on non-contrast CT 1, 2:

• If <10 HU (lipid-rich adenoma), pheochromocytoma screening can be omitted unless symptoms are present 1
• If ≥10 HU or indeterminate, proceed with full pheochromocytoma screening 1

Common Pitfalls to Avoid

• Never skip cortisol screening even for small masses—autonomous cortisol secretion occurs in 5-30% of incidentalomas and impacts morbidity through metabolic complications 1, 2
• Never perform adrenal biopsy before ruling out pheochromocytoma, as this can precipitate hypertensive crisis 1
• Do not assume a small mass is non-functional—even 1.5 cm masses can be hormonally active, particularly for aldosterone-secreting adenomas 3
• Recognize that co-secretion of multiple hormones (cortisol + androgens, cortisol + catecholamines) can occur and raises concern for ACC 4, 5, 6

Ancillary Testing if Abnormalities Found

• If cortisol hypersecretion confirmed: measure plasma ACTH to confirm ACTH-independent secretion 1
• If primary aldosteronism confirmed: perform adrenal vein sampling before considering surgery to lateralize the source 1
• If pheochromocytoma suspected: consider genetic testing for hereditary syndromes (VHL, MEN2, familial paraganglioma) 1