From the Guidelines
The workup for an adrenal mass should begin with a thorough clinical evaluation, including a focused history and physical examination, and should include hormonal evaluation and imaging characteristics to determine malignancy risk, as recommended by the most recent guidelines 1. The clinical evaluation should aim to identify signs and symptoms of adrenal hormone excess, adrenal malignancy, and/or extra-adrenal malignancy.
- All patients with adrenal masses should undergo hormonal evaluation, including:
- 1mg overnight dexamethasone suppression test to screen for autonomous cortisol secretion
- Plasma free metanephrines or 24-hour urinary metanephrines and catecholamines to screen for pheochromocytoma
- Serum potassium and aldosterone-to-renin ratio to screen for primary aldosteronism if hypertensive
- Imaging characteristics are crucial for determining malignancy risk, with non-contrast CT being the initial study of choice, as it can help distinguish benign lesions from those that require further radiologic investigation 1.
- Masses larger than 4cm, with irregular borders, heterogeneous appearance, or Hounsfield units >10 on non-contrast CT warrant surgical evaluation.
- For indeterminate masses, additional imaging with contrast-enhanced CT washout studies or MRI may be helpful.
- Functional adrenal masses generally require surgical removal regardless of size.
- For non-functional adenomas <4cm with benign imaging characteristics, follow-up imaging at 6-12 months is recommended to ensure stability.
- Adrenal biopsies are rarely indicated and should be avoided if pheochromocytoma is suspected due to risk of hypertensive crisis. The rationale for this approach is that approximately 15% of adrenal incidentalomas are hormonally active, and early identification of functional tumors or malignancies allows for appropriate intervention before complications develop, as supported by the most recent guidelines 1.
From the Research
Adrenal Mass Work-up
- The work-up of incidental adrenal masses (adrenal incidentalomas) is a common finding during imaging, present in up to 5% of computed tomography (CT) scans performed on the general population 2
- The best approach to manage these lesions is still under discussion, but recent literature and available guidelines suggest the use of unenhanced and contrast-enhanced CT, with laboratory tests to exclude functional lesions, as the most sensitive and specific methods currently available for characterization of adrenal masses 2
- Magnetic resonance imaging, positron emission tomography-CT, and fine-needle aspiration biopsy can be used as adjunct diagnostic tools in indeterminate lesions, but are rarely indicated 2
- The evaluation of an incidental adrenal mass typically involves three components:
- Clinical assessment
- Review of the images
- Biochemical testing, with the goal of ruling out malignancy and identifying hormonally active lesions 3
- The intensity of the approach to the patient with an incidental adrenal mass is tailored to the clinical situation, ranging from a quick evaluation to a detailed work-up 3
- Follow-up is required for lesions that are not treated surgically, and an improved identification of benign lesions is warranted to reduce the number of unnecessary surgeries and follow-up examinations in patients with benign lesions 2