How is an adrenal adenoma treated?

Adrenal adenomas are benign tumors arising from the cortex of the adrenal gland. Most are nonfunctioning—meaning they do not secrete excess hormones—and are discovered incidentally during imaging studies performed for unrelated reasons (so-called “incidentalomas”). Management depends on tumor size, hormonal activity, imaging characteristics, and clinical context.

For nonfunctioning adrenal adenomas smaller than 4 cm with benign-appearing features on CT or MRI (e.g., homogeneous attenuation <10 Hounsfield units on noncontrast CT, rapid contrast washout), surveillance is typically recommended. This usually involves repeat imaging (e.g., CT or MRI) at 6–12 months to assess for growth, followed by less frequent monitoring if stable. Biochemical evaluation—including measurement of plasma free metanephrines (to rule out pheochromocytoma), serum aldosterone and renin (for primary aldosteronism), and a low-dose dexamethasone suppression test (for Cushing syndrome)—is essential at diagnosis and may be repeated periodically if clinical suspicion arises.

Adrenalectomy is indicated for functioning adenomas (e.g., cortisol- or aldosterone-secreting tumors causing Cushing syndrome or primary aldosteronism), tumors ≥4–6 cm in diameter (due to increased risk of malignancy), or those demonstrating suspicious imaging features (e.g., heterogeneity, irregular margins, delayed contrast washout, or size increase >20% or >2 cm over serial imaging). Laparoscopic adrenalectomy is the preferred surgical approach for most patients, offering faster recovery and fewer complications compared with open surgery.

Patients with hormone-secreting adenomas require preoperative medical optimization—for example, alpha-blockade for pheochromocytoma (though rare in adenomas), mineralocorticoid receptor antagonists for aldosteronism, or glucocorticoid replacement planning for Cushing syndrome. Postoperatively, endocrine follow-up is critical to monitor for resolution of hormonal excess, adrenal insufficiency (especially after bilateral or contralateral adrenal disease), and long-term recurrence.

Referral to an endocrinologist and a high-volume adrenal surgeon is strongly advised to ensure appropriate biochemical workup, imaging interpretation, and surgical decision-making. Multidisciplinary evaluation significantly improves diagnostic accuracy and outcomes.