What is the management approach for a 2 cm right adrenal adenoma?

Management of a 2 cm Right Adrenal Adenoma

For a 2 cm adrenal adenoma, perform complete hormonal screening immediately, confirm benign imaging characteristics with unenhanced CT (≤10 HU), and if both are reassuring, no further follow-up imaging or hormonal testing is required. 1

Immediate Initial Steps

Mandatory Hormonal Evaluation

Every patient with an adrenal incidentaloma requires complete hormonal screening regardless of size or imaging appearance 2, 1:

• 1 mg overnight dexamethasone suppression test to exclude autonomous cortisol secretion (cortisol ≤50 nmol/L or ≤1.8 µg/dL indicates no autonomous secretion) 2, 3
• Plasma free metanephrines or 24-hour urinary fractionated metanephrines to exclude pheochromocytoma 2, 3
• Aldosterone-to-renin ratio only if the patient has hypertension or unexplained hypokalemia 4, 5

This hormonal workup is critical because functional adenomas occur in approximately 37-40% of incidentalomas, and many patients lack obvious clinical symptoms at presentation 6.

Radiological Characterization

Obtain unenhanced CT as the mandatory first-line imaging 2:

• Homogeneous lesions ≤10 HU are definitively benign regardless of size and require no additional imaging 2, 1
• If attenuation is >10 HU, perform either contrast washout CT or chemical shift MRI to confirm benign nature 1, 7
• At 2 cm, this mass has very low malignancy risk, as masses <3 cm are typically benign 1

Management Algorithm Based on Results

If Non-Functioning AND Benign Imaging (≤10 HU)

No further follow-up imaging or functional testing is required 1. This represents the definitive endpoint for management.

The evidence here is clear: multiple guidelines (ACR, ESE) agree that benign-appearing, non-functioning adenomas <3 cm with confirmed benign imaging characteristics need no surveillance 2, 1.

If Mild Autonomous Cortisol Secretion (MACS) Detected

If post-dexamethasone cortisol is >50 nmol/L (>1.8 µg/dL) without overt Cushing's syndrome 3:

• Screen aggressively for and treat cortisol-related comorbidities including hypertension, type 2 diabetes, and osteoporosis 2, 3
• Consider surgery in an individualized approach if relevant comorbidities are present and potentially attributable to cortisol excess 3
• These patients harbor increased risk of morbidity and mortality even without overt Cushing's syndrome 3

If Any Hormonal Hypersecretion Confirmed

Surgery is indicated for any hormonally active tumor 2:

• Laparoscopic adrenalectomy for cortisol-secreting or aldosterone-secreting adenomas 1
• Adrenalectomy after appropriate alpha-blockade for pheochromocytoma 1

If Indeterminate Imaging

Multidisciplinary discussion is mandatory when imaging characteristics are indeterminate 4, 2. Options include:

• Repeat imaging in 6-12 months 4, 7
• Additional imaging modalities immediately 4
• Surgical resection based on patient preference and overall health 4

Critical Pitfalls to Avoid

Never perform adrenal biopsy routinely - only consider when metastatic disease from extra-adrenal malignancy would directly change management, and only after pheochromocytoma is definitively excluded 2. Failure to exclude pheochromocytoma before biopsy or surgery can be fatal 2.

Do not skip pheochromocytoma screening even if the patient appears asymptomatic, as this is a life-threatening condition that must be excluded before any intervention 2, 8.

Do not assume benign imaging alone is sufficient - hormonal evaluation is mandatory because functional adenomas can appear radiologically benign and may lack obvious clinical symptoms 1, 6.

Special Considerations for This 2 cm Mass

At 2 cm, this adenoma falls well below the 4 cm threshold where malignancy risk increases significantly 4, 2. The primary concern is excluding hormonal hypersecretion rather than malignancy. If imaging shows ≤10 HU and hormonal workup is normal, this represents a definitive benign, non-functioning adenoma requiring no further action 2, 1.