Located above the kidneys, the two adrenal glands are part of the body's hormonal (endocrine) system. The outer layer of each gland — called the adrenal cortex — releases hormones that regulate metabolism, blood pressure, and characteristics such as hair growth and body shape. The inner region of each gland — called the adrenal medulla — makes hormones that control responses to physical and emotional stress.
Hormones produced by the adrenal glands include:
This hormone, which is released by the adrenal cortex, aids in metabolism and helps the body recover from physical stress due to surgery, injury, and infection.
Produced in the adrenal cortex, this hormone regulates blood levels of sodium and potassium, which affect blood pressure and the balance of fluids and electrolytes.
A precursor to male and female sex hormones (androgens and estrogens, respectively) produced by the adrenal cortex, DHEA levels typically decrease after age 30.
Catecholamines include epinephrine (adrenaline) and norepinephrine (noradrenaline), the “fight or flight” hormones released by the adrenal medulla that help the body respond to stress or fear. They can increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness.
Benign, Functional, and Malignant Tumors
Benign (noncancerous) adrenal tumors — called adenomas or nodules — are common, and are often found incidentally during diagnostic imaging for an unrelated health problem. About 5 to 10 percent of adrenal nodules are malignant (cancerous). Functional hormone testing can help distinguish between benign and malignant adrenal tumors.
Functional (hormone-producing) adrenal tumors may be found during tests to investigate hormone-related symptoms. Functional tumors cause a wide variety of symptoms, depending on which hormones they produce. Most functional tumors are benign, but a few are malignant and can spread (metastasize) beyond the adrenal gland to other parts of the body.
Malignant tumors of the adrenal glands are rare. An estimated 300 to 500 new cases of adrenal cancer occur in the United States each year. The most common type of adrenal cancer is adrenal cortical carcinoma. There are few known risk factors for adrenal cortical carcinoma, although people with certain genetic conditions may have a higher risk of developing this type of cancer.
Types of Adrenal Tumors
The treatment your doctor recommends will depend on what kind of adrenal tumor you have. The following are the most common types of adrenal tumors. Follow the links for more specific information about each tumor type, and how it is treated.