About the adrenal glands

The adrenals are small glands that sit above each of the kidneys. The kidneys are located deep inside the upper part of the abdomen.

The adrenal gland is made up of 2 parts. The outer part, called the cortex, is where the adrenal cortical tumors develop. The function of the cortex is to produce certain hormones for the body. These hormones all possess a similar chemical structure and are called steroids. They include:

• cortisol -- causes changes in metabolism that help the body to handle stress.
• aldosterone -- helps the kidneys regulate the amount of salt in the blood and tissues of the body.
• androgens and estrogens -- In men, the testicles produce most of the androgens (male hormones). The ovaries produce most of the estrogens (female hormones) in women. However, the adrenal glands produce small amounts of both androgens and estrogens in men and women.

The inner portion of the adrenal gland, called the medulla, is really an extension of the nervous system. Nervous system hormones such as norepinephrine and epinephrine (also called adrenaline) are made in the medulla. Tumors of the adrenal medulla, such as pheochromocytomas and neuroblastomas, are not discussed in this document. (For more information on neuroblastomas, see our document, Neuroblastoma.)

Adrenal cortex tumors

There are 2 main types of adrenal cortex tumors: benign (non-cancerous) and malignant (cancers). Most of these tumors are benign and are called adenomas. Cancers of the adrenal cortex are rare. These 2 types of tumors can be hard to tell apart when the cells are looked at under the microscope. There are certain features to look for, but the only way to know for sure that the tumor is a cancer is when it has spread. If it has spread to lymph nodes or other organs and tissues, it is a cancer. Adenomas do not spread outside the adrenal gland.

Adrenal cortex adenomas

Most tumors of the adrenal cortex are benign adenomas. These are small tumors, usually less than 5 centimeters (about 2 inches) in diameter. They usually occur in only 1 adrenal gland, but sometimes affect both glands.

Most people with adrenal adenomas have no symptoms and are unaware that they have an adrenal tumor. Some of these adenomas are discovered "incidentally" (by accident) when CT or MRI scans of the abdomen are done because of unrelated health problems. About 5% of people who have a CT scan of the abdomen are found to have an adrenal tumor that was not suspected. Most of these are nonfunctional -- meaning that they don't make adrenal hormones. Sometimes these tumors are known by the nickname "incidentalomas" because they aren't causing problems and were only found by accident.

Some adenomas produce too much adrenal steroid hormone. Sometimes the excess hormone can cause symptoms. Many of the hormone-related symptoms of adenomas are the same as those from adrenal carcinomas (cancers). These symptoms are discussed in the section, "Can adrenal cortical cancer be found early?" Adenomas are much more likely than carcinomas to produce high levels of aldosterone, which can cause high blood pressure.

Treatment: Adenomas can be cured by removal of the adrenal gland that contains the adenoma. Some adrenal adenomas that cause hormone-related symptoms can be treated effectively with medications that block the production or actions of these hormones. This may be the best treatment choice for patients with other serious medical problems who might not be able to withstand a major operation.

The treatment of incidentalomas depends on the chance that it may be a cancer and whether or not it is raising hormone levels. When an adrenal tumor is found accidentally, tests are often done to see if it is making hormones. If it is, surgery is often recommended. Otherwise, surgery may only be recommended if it is likely to be a cancer. Tumors that are small are less likely to be cancer, and are often watched without treatment. The CT (or MRI) scan is repeated at least 6 months later to see if the tumor has grown. If it has, it may need to be removed. If it hasn't grown, hormone levels will be watched over the next few years. If the tumor remains small and doesn't make any hormones, it may not need to be treated at all.

The remainder of this document refers to adrenal cancers only, and not to adenomas.

Adrenal cortical cancer

The type of cancer that develops in the cortex of the adrenal gland is called adrenal cortical carcinoma. It is discovered for 1 of 2 reasons. The first is that it produces hormones that cause body changes such as weight gain and fluid retention, early puberty in children, or excess facial or body hair growth in women.

They can also be discovered when they start causing symptoms because they have gotten very large. Large tumors can press on other organs in the abdomen, causing pain, a feeling of fullness that causes people to eat less, and weight loss. Generally, adrenal cortical cancers are much larger than adrenal adenomas. An adrenal tumor larger than 5 or 6 centimeters (about 2 to 2 1/2 inches) is assumed to be a cancer. In one study, the average size of an adrenal cancer was about 13 cm (or 5 inches).

Most cancers found in the adrenal gland did not start there and are not adrenal cortical cancers. Instead, they start in other organs or tissues and then spread (metastasize) through the bloodstream to the adrenal glands. For example, lung cancers and breast cancers often spread to the adrenals. Even when other cancers spread to the adrenals; however, they are still named after the place they started and are treated like other cancers that start in the same place. They are not considered to be adrenal cancer. Their treatment is described in our documents on these cancers.

Last Medical Review: 03/20/2009
Last Revised: 03/20/2009