Adrenal Adenoma
An adrenal adenoma is a common benign (non-cancerous) tumor that forms in one of the adrenal glands, which sit above the kidneys. Most adrenal adenomas are “non-functioning,” meaning they do not produce excess hormones and are discovered incidentally during imaging done for unrelated reasons. Some, however, can produce hormones such as cortisol, aldosterone, or androgens, leading to specific symptoms or medical conditions.
What is it?
An adrenal adenoma is a benign growth that develops from the outer layer of the adrenal gland (the cortex). Many are discovered as “incidentalomas”—unexpected findings on CT or MRI scans performed for other reasons. Adenomas may be classified as functioning or non-functioning based on whether they produce hormones. Functioning adenomas can cause conditions such as Cushing’s syndrome, primary aldosteronism, or androgen excess.
Imaging helps differentiate benign adenomas from other adrenal masses, such as metastases or adrenal cancer. Characteristic features on CT—such as low density due to fat content or rapid contrast washout—often confirm the diagnosis without biopsy. MRI is also useful when features are not definitive on CT.
Important to Know
Most adrenal adenomas do not require treatment and remain stable over time. However, functioning adenomas can lead to significant health issues if not recognized. Blood and urine tests are often recommended to evaluate hormone levels, especially when symptoms or imaging features raise concern.
Red flag symptoms include new or worsening high blood pressure, unexplained weight gain, muscle weakness, excessive thirst, or changes in potassium levels. Larger adenomas or those with atypical imaging features may require closer monitoring or surgical evaluation. Follow-up imaging may be recommended to ensure stability.