An adrenal adenoma is a benign (non-cancerous) tumor that forms within an adrenal gland—the hormone-producing gland located on top of each kidney. Whether or not an adrenal adenoma causes symptoms depends on if it is classified as “functional” (hormone-producing) or “non-functional” (non-hormone producing).  

Non-functional adrenal adenomas may progress to functional ones over time, however, they do not progress to cancer.  

People typically have one adrenal adenoma, affecting only one of the two adrenal glands. The condition is more common among women than men, and in older adults. By age 70, about 10% of all people may have adrenal adenomas. However, because most adrenal adenomas don’t cause symptoms, many people don’t realize they have one.  

Treatment isn’t necessary for non-functional adrenal adenomas. But when adrenal adenomas are functional, treatments are available to manage, and even cure, the condition.

An adrenal adenoma is a type of benign (non-cancerous) tumor that is located in an adrenal gland.  

An adrenal gland is a small organ that is located above each kidney. The glands are part of the endocrine system and are responsible for secreting hormones. Each portion of an adrenal gland secretes different hormones:

• The inner portion (medulla) secretes catecholamines (i.e., adrenaline), which help to control a person’s heart rate, blood pressure levels, perspiration, and stress-related responses.
• The outer portion (cortex) secretes hormones such as cortisol, which helps to control metabolism, suppress inflammation, and manage stress-related responses; aldosterone, which controls the balance between salt and water in the body; and sex hormones, including estrogen and androgens like testosterone.

As mentioned above, a non-functional adrenal adenoma does not typically cause symptoms. That’s because the tumor doesn’t cause any changes to hormone secretion. But if the tumor’s presence causes the adrenal gland’s cortex to secrete increased levels of certain hormones, symptoms may begin to develop and the tumor is considered to be functional.  

In some cases, higher levels of hormones can lead to serious conditions. When an adrenal adenoma causes the adrenal gland to secrete higher levels of cortisol, for example, a person may develop hypercortisolism, or Cushing’s syndrome, which causes excessive weight gain, abnormal fat distribution, abdominal striae (stretch marks), and osteoporosis. When higher levels of aldosterone are secreted, a person may develop primary aldosteronism or Conn syndrome, characterized by difficult-to-control hypertension, and in some cases, severe hypokalemia (low potassium levels).  

In rare cases, an adrenal adenoma may cause the adrenal gland to secrete higher-than-normal levels of the sex hormones estrogen or testosterone, which may lead to symptoms like enlarged breasts in males or excess facial and/or body hair in females.

Most people with adrenal adenoma do not know that they have the condition because they don’t experience any symptoms. Non-functional adrenal adenomas are significantly more common than functional ones, which cause symptoms.  

When people have functional adrenal adenomas, their symptoms may differ, depending on the type of hormone that is secreted in excess.  

People who secrete higher-than-normal levels of cortisol may notice:

• Increased levels of body fat in the torso
• Obesity
• Fatigue
• Muscle weakness
• High blood pressure
• Type 2 diabetes (i.e. high blood sugar levels)
• Osteoporosis
• Bruising on the upper portion of the body
• Purple stretch marks that appear on the upper portion of the body
• Depression
• Puffiness or swelling of the face
• Menstrual cycle irregularities
• Facial hair and acne, among women
• Fungal infections

People who secrete higher-than-normal levels of aldosterone may notice:

• Fatigue
• Headaches
• Muscle weakness
• Numbness
• High blood pressure that’s hard to control with medication
• Lower-than-normal levels of potassium in the blood
• Lower-than-normal levels of magnesium in the blood
• Higher-than-normal levels of sodium in the blood

People who secrete higher-than-normal levels of sex hormones may notice:

• Excess facial or body hair, deeper voice, bulkier muscles, baldness or acne among females
• Breast enlargement among males

Some people may inherit conditions that increase their risk of adrenal adenoma, including:

• McCune Albright syndrome (GNAS1 genetic mutation)
• Multiple endocrine neoplasm type 1 (MENIN genetic mutation)
• Hereditary bilateral adrenal adenoma (ARMC5 genetic mutation)
• CTNNB1 genetic mutation
• PRKACA genetic mutation
• KCNJ5 genetic mutation
• ATP1A1 genetic mutation
• ATP2B3 genetic mutation
• CACNA1D genetic mutation
• CTNNB1 genetic mutation

People are more likely to develop adrenal adenomas if they:

• Smoke tobacco products
• Use smokeless tobacco

Many adrenal adenomas are discovered incidentally when doctors are trying to diagnose another condition. An imaging study (CT scan or MRI) of the abdomen, for example, may show the presence of a non-functional adrenal adenoma.  

Other times, adrenal adenomas are diagnosed after a patient notices symptoms. In these cases, doctors can diagnose the condition after learning about a patient’s medical history, performing a physical exam, and offering diagnostic tests.  

During the medical history, you should tell your doctor if you have high blood pressure, type 2 diabetes, or certain inherited conditions like multiple endocrine neoplasia syndromes. You should also discuss any recent, unintentional changes in your weight.  

During a physical exam, doctors may look for signs of an adrenal adenoma, such as an apple-shaped torso, purple-colored stretch marks on your torso, bruising, excess facial/body hair on female patients, or enlarged breasts on male patients.  

Blood tests or urine tests may be used to check your hormone levels. High levels of cortisol or aldosterone, as well as estrogen and testosterone, may suggest an adrenal adenoma. Blood tests may also reveal low levels of potassium or magnesium or high levels of sodium, which may be signs of adrenal adenoma.  

Imaging tests, such as CT scans or MRIs, may be used to diagnose an adrenal adenoma. It is often possible to use an imaging study to confirm that the tumor is noncancerous.  

In some instances when results are unclear, a fine-needle biopsy may be needed to confirm that the tumor is a benign adrenal adenoma and not cancer; this procedure should only be performed after a functional work-up of the gland has been completed and has confirmed it is a non-functional tumor.

Treatment depends on the type of adrenal adenoma.  

• Non-functional adrenal adenoma: Treatment for non-functional adrenal adenoma is usually not necessary. Instead, a watch-and-wait approach may be recommended. Initially, you may be sent for imaging studies at least twice a year to ensure that the adrenal adenoma isn’t growing. Blood or urine tests might be required to check hormone levels, to ensure that the non-functional adrenal adenoma isn’t evolving into a functional adrenal adenoma. In certain cases, non-functional tumors can grow over time; if they get large enough to cause pain, they may need to be removed surgically. 
  
• Functional adrenal adenoma: Functional adrenal adenoma is usually treated with surgery. After these benign tumors are removed, symptoms usually disappear; the procedure is curative for most people, however in cases of long-standing hypertension, some patients will still require medication to normalize their blood pressure.

The majority of people who have an adrenal adenoma will never learn that they have the condition, and it won’t cause unwanted effects on their health.  

When a non-functional adrenal adenoma is diagnosed, doctors may track its progress two or more times during the first year, then annually for a year or two, then every five years. If the tumor grows in size or begins to exhibit symptoms, it can be treated with surgery or medication. When a functional adrenal adenoma is diagnosed and treated, it shouldn’t have long-term effects on a person’s health.

“The Yale Smilow Cancer Center is a center of excellence for the management of adrenal adenomas,” says Smilow Cancer Hospital endocrine surgeon Courtney Gibson, MD. “Our multidisciplinary endocrine neoplasia team, consisting of expert endocrinologists, endocrine surgeons, radiologists, and pathologists, provide world-class expertise in the work-up, diagnosis, and treatment of these tumors.”