Adrenal Mass Evaluation
An adrenal gland is a small organ that resides near the upper portion of each kidney. These glands produce hormones (such as adrenaline) that control metabolism, fluid balance, blood pressure, and responses to stress. They are responsible for the boost in energy you feel when you are in “fight or flight” mode, such as in a fight or extreme sporting situation. In addition, they produce small amounts of “male” and “female” hormones (androgens), although most of the sex hormones are produced by the testicles or ovaries.
Since other medical conditions and pharmaceutical use can mimic adrenal disorders, a detailed evaluation of a patient with an adrenal mass is essential. Treatment recommendations are based on both how the glands look in x-rays and chemical behavior. The patient’s medical history and results of physical examinations can reveal important information regarding the possible abnormal production of hormones from an adrenal mass. Some of the conditions associated with adrenal masses and abnormalities include:
- Steroid excess (Cushing’s syndrome)
- Easy bruising
- Fluid retention
- Skin “stretch” marks (striae)
- Characteristic changes in body shape
- Aldosterone excess (Conn’s syndrome)
- Catecholamine (adrenaline-like hormone) excess (pheochromocytoma)
- Fluctuating (paroxysmal) hypertension
Once an adrenal mass is discovered, specific laboratory testing is recommended in all cases.
- Blood chemistry (most importantly sodium, potassium, and glucose)
- 24-hour urine testing for “urinary-free cortisol” or performance of overnight dexamethasone suppression test (tests body’s response to oral administration of steroid)
- Plasma-free metanephrines (blood test checking for excess adrenaline-like substance)
When any of these screening tests are abnormal, more advanced tests can confirm the results, including serum (blood) aldosterone:renin ratio, a two-day dexamethasone suppression test, and 24-hour urine testing for potassium and catecholamines.
Occasionally additional imaging beyond x-rays is helpful to determine the type of benign mass or the presence of malignancy (originating in the adrenal gland or from cancer in another organ).
- CT scan (using a very specific method for the adrenal gland)
- MRI scan
- Adrenal vein sampling (radiologist places small tube directly into adrenal vein to test for excess hormones) MIBG nuclear scan (rarely used)
- PET scan (sometimes used when known history of malignancy elsewhere)
Most adrenal tumors that produce excess hormones are best treated with laparoscopic adrenalectomy (surgical removal). Small non-functioning adrenal masses that are convincingly benign on x-ray findings usually require no treatment. However, if there is any possible suspicion of malignancy, close follow-up, biopsy, or surgical removal should be considered.