Incidental adenomas of the adrenal gland — commonly called incidentalomas — are tumors that are found unexpectedly during diagnostic imaging for an unrelated health problem. An estimated 5 percent of CT or MRI scans of the abdomen in people age 50 or older reveal small nodules in the adrenal cortex. Most incidentalomas are benign, nonfunctional (non-hormone-producing) growths, but a small number are either malignant or functional (hormone-producing) tumors and require removal.
High blood pressure is the most common sign of a functional incidentaloma. Additional symptoms may include:
- muscle weakness
However, patients with an incidentaloma may not have any noticeable signs or symptoms. In addition, many patients initially attribute symptoms caused by excess adrenal hormones to other health conditions.
If an incidentaloma is discovered, an endocrinologist, surgeon, or other specialist will administer a variety of laboratory tests to determine if the tumor is functional. These initial screening tests reveal whether the tumor is making excess cortisol, aldosterone, or catecholamines (epinephrine and norepinephrine). If the initial screening tests are positive, the specialist may order more hormone tests and also may sample the hormones produced separately by each adrenal gland to help confirm the diagnosis. Additional imaging tests may be necessary to further define the incidentaloma.
Surgery is not usually necessary for patients with small, nonfunctional incidentalomas. Regular follow-up with hormone tests and imaging studies may be appropriate for these patients.
Surgery is the primary treatment for functional, hormone-producing tumors. After surgery, some patients may require temporary treatment with medications until normal adrenal gland function and hormone levels are restored. Many patients may be able to decrease or stop taking medications to control high blood pressure and diabetes after a functional adrenal tumor is removed.