Adrenal (Suprarenal Gland) Masses

The adrenal glands, also called the suprarenal glands, are small organs located at the top of each kidney. They produce hormones that are vital for life, such as cortisol, aldosterone and adrenaline. These hormones help to regulate blood pressure, blood sugar, the balance of fluid and salt, and the body’s response to stress.

An adrenal mass is an area of tissue in the adrenal gland that looks different from normal. A large proportion of these masses are noticed by chance during a computed tomography (CT) or MRI scan carried out for another reason. For this reason they are called “adrenal incidentalomas”, that is, adrenal masses found by chance.

The great majority of adrenal masses are benign. The most common type is an adrenal adenoma. Other possibilities include a cyst, a myelolipoma containing fatty tissue, a phaeochromocytoma that can secrete hormones and, much more rarely, cancer of the adrenal gland or the spread of another cancer to the adrenal gland.

When an adrenal mass is found, answers are sought to two basic questions:

1. Is the mass producing more hormone than it should?
2. Do its imaging features look benign, or do they raise a suspicion of cancer?

The treatment and follow-up plan is decided according to the answers to these two questions [1].

Does an adrenal mass cause symptoms?

Most adrenal masses do not secrete hormones and do not cause any symptoms. Masses that do cause symptoms usually produce more hormone than normal. The complaints that may arise vary according to the hormone produced.

Excess cortisol

Markedly excessive secretion of cortisol is called “Cushing’s syndrome”. The following symptoms may occur:

• Weight gain, especially around the abdomen and trunk
• Rounding of the face
• Thinning of the skin and easy bruising
• Muscle weakness
• Raised blood pressure or blood sugar
• Osteoporosis (bone thinning) and an increased risk of fractures
• Irregular periods in women

Some patients do not have the typical outward appearance of Cushing’s syndrome, but their cortisol production is mildly increased. This condition is called “mild autonomous cortisol secretion”. It may be associated in particular with high blood pressure, type 2 diabetes and osteoporosis. In these patients, the decision on surgery is not based on the hormone result alone; age, accompanying illnesses, the features of the mass and the patient’s preferences are assessed together [1].

Excess aldosterone

Excessive production of the hormone aldosterone can raise blood pressure and lower the level of potassium in the blood. As a result, the following

• Blood pressure that cannot be controlled despite medicines
• Needing to take more than one blood pressure medicine
• Muscle weakness or cramps
• Tiredness
• Palpitations

may occur.

Excess adrenaline-like hormones

Tumours called phaeochromocytomas can produce too much adrenaline and similar hormones. In some patients, the following complaints occur in attacks:

• Palpitations
• Severe headache
• Heavy sweating
• Trembling and a feeling of anxiety
• A sudden rise in blood pressure
• Chest or abdominal pain

These symptoms may not always occur together. When a phaeochromocytoma is suspected, it is very important that hormone tests are completed before any surgery or biopsy.

Excess sex hormones

Rarely, adrenal masses can produce too much male or female hormone. In women, rapidly developing hair growth, deepening of the voice and irregular periods may be seen; in men, breast enlargement or changes in sexual function may occur. If these symptoms are present, assessment should be carried out without delay.

Why do adrenal masses develop?

In most masses, no definite cause can be identified. They become more common with age. Some rare inherited conditions can create a predisposition to adrenal tumours. In people who have previously been diagnosed with another cancer, a mass found in the adrenal gland is also assessed to see whether it is a metastasis.

The assessment is made by looking at the patient’s history, the examination, imaging and hormone tests together.

How is the imaging assessed?

Thin-slice computed tomography is usually used to assess an adrenal mass. Where necessary, MRI or special scanning methods may also be used.

The following features are examined on imaging:

• The size of the mass
• Whether its borders are regular
• Whether its internal structure is uniform or irregular
• The density value measured on non-contrast CT
• Its relationship with the surrounding tissues
• Whether it has grown compared with previous scans

Masses that look uniform on non-contrast CT and have a density value of 10 Hounsfield units or below are very largely consistent with a benign adenoma. According to current guidelines, in masses that clearly have these features, repeated imaging simply because of their size is usually not necessary [1].

If the imaging result is not conclusive, further investigations such as adrenal-specific CT, MRI or, in selected patients, PET-CT may be carried out. Where possible, this decision should be made through a joint assessment by specialists in radiology, endocrinology and surgery.

Which hormone tests are carried out?

The tests requested depend on the patient’s symptoms, blood pressure and the imaging features of the mass. The assessment may include:

• An overnight low-dose dexamethasone suppression test to look for excess cortisol
• Blood or urine metanephrine tests if a phaeochromocytoma is suspected
• Measurement of aldosterone and renin if there is high blood pressure or an unexplained low potassium level
• Certain sex hormones and hormone precursors if adrenal cancer is suspected

According to current guidelines, some patients whose mass has the typical appearance of a benign adenoma on non-contrast CT may not need a test for phaeochromocytoma. On the other hand, if the imaging is not typical, it is important to rule out a phaeochromocytoma with metanephrine tests. Which tests are needed should be decided following an endocrinology assessment [1].

Is a needle biopsy needed?

Needle biopsy is not routinely carried out for adrenal masses. A biopsy cannot always reliably distinguish between a benign adrenal adenoma and cancer of the adrenal gland.

A biopsy may be considered mainly in selected patients who have cancer of another organ and in whom knowing whether the adrenal mass is a metastasis would change the treatment. A phaeochromocytoma must be ruled out before the procedure. Carrying out a biopsy on a hormone-secreting phaeochromocytoma without preparation can cause a severe rise in blood pressure and heart and circulation problems [1].

Does every adrenal mass need surgery?

No. Most masses that do not secrete hormones and clearly have benign features on imaging do not need surgery.

The decision on surgery is not made by looking only at the diameter of the mass. The following features are assessed together:

• Whether it produces hormones
• Its appearance on CT or MRI
• The size of the mass
• Whether it grows during follow-up
• The patient’s age and general state of health
• Any previous history of cancer
• The expected benefits and risks of surgery
• The patient’s preferences

In which situations may surgery be considered?

Surgery generally comes into consideration in the following situations:

• Masses that secrete clinically significant amounts of hormone
• Phaeochromocytoma
• A one-sided aldosterone-producing adenoma
• A mass causing marked excess of cortisol
• Suspicion of adrenal cancer on imaging
• An indeterminate mass that shows significant growth during follow-up
• A mass causing symptoms by pressing on neighbouring organs

The idea that every mass of about 4 centimetres or more must be operated on does not fully reflect the current approach. Nevertheless, in masses that are 4 centimetres or larger, have an irregular internal structure or have a high CT density, the possibility of cancer is assessed more carefully. For these patients, an assessment by a multidisciplinary team is usually recommended [1].

In masses that secrete mild amounts of cortisol, the decision on surgery is individual. The possible benefit of surgery may be considered particularly in patients with hard-to-treat high blood pressure, diabetes or osteoporosis.

How is the operation performed?

The operation to remove the adrenal gland is called “adrenalectomy”. In suitable patients, the operation can be carried out laparoscopically or robotically, through a few small incisions in the abdomen. These methods generally mean less pain and a shorter recovery time.

Open surgery may be needed for masses that are large, are suspected of having spread to surrounding tissues or suggest adrenal cancer. It is important that a mass suspected of being cancer is removed without breaking it up and together with the necessary surrounding tissue. It is recommended that these operations are carried out in centres experienced in adrenal surgery [2,3].

Is it necessary to take medicines before the operation?

Special preparation may be needed for hormone-secreting masses.

In patients diagnosed with a phaeochromocytoma, medicines called alpha-blockers are usually used before the operation to stabilise blood pressure and heart rate. In most patients, this preparation starts about 7–14 days before the operation. Fluid and salt intake is also adjusted under medical supervision, taking into account the patient’s heart and kidney condition. Operating directly without using these medicines can cause severe swings in blood pressure [4].

In masses that secrete cortisol, on the other hand, support with cortisone-containing medicines may be needed during and after the operation. The dose of these medicines is set by the endocrinology team according to the hormone results.

Related operationLaparoscopic Adrenalectomy →Read how the operation is performed and what recovery involves →

After minimally invasive (keyhole) adrenal operations, the hospital stay for most patients is about 1–3 days. After open operations or in people with additional health problems, this period may be longer.

In the first days there may be pain at the incision sites, tiredness, loss of appetite and difficulty moving. Starting light walks early on is generally recommended. Most patients can return to daily life and desk work within about 2–3 weeks. After open surgery or in the case of heavy physical work, a longer recovery period may be needed.

When a cortisol-secreting mass is removed, it may take time for the other adrenal gland to resume normal hormone production. During this period, cortisone-containing medicines may need to be taken. These medicines should not be reduced or stopped without a doctor’s advice.

After the operation, the following

• Pathology result
• Blood pressure and blood sugar
• Potassium level
• Cortisol and other necessary hormones
• Doses of the medicines being taken

are checked. The follow-up plan is prepared individually according to the type of mass and the hormone results.

If fever, abdominal or back pain that keeps getting worse, persistent vomiting, shortness of breath, a feeling of fainting, or redness or discharge at the wound develops, you should contact your healthcare team.

How are masses that are not operated on followed up?

In masses that are clearly benign on imaging and do not secrete hormones, repeated imaging at regular intervals is usually not necessary. Repeating hormone tests continually is also not recommended unless a new symptom develops or conditions such as high blood pressure and diabetes get worse [1].

In masses whose imaging result is not conclusive but for which surgery has not been decided, a follow-up CT or MRI within 6–12 months may generally be considered. At this check, growth of more than 20 per cent in the diameter of the mass, together with growth of at least 5 millimetres, may be important for reassessment and for the question of surgery [1].

The follow-up plan is not the same for every patient. It is set individually, taking into account age, the appearance of the mass, the hormone results and accompanying illnesses.

1. Fassnacht M, Tsagarakis S, Terzolo M, et al. European Society of Endocrinology Clinical Practice Guidelines on the Management of Adrenal Incidentalomas, in collaboration with the European Network for the Study of Adrenal Tumors. European Journal of Endocrinology. 2023;189(1):G1–G42. https://academic.oup.com/ejendo/article/189/1/G1/7198474
2. Yip L, Duh QY, Wachtel H, et al. American Association of Endocrine Surgeons Guidelines for Adrenalectomy: Executive Summary. JAMA Surgery. 2022;157(10):870–877. https://pubmed.ncbi.nlm.nih.gov/35976622/
3. Fassnacht M, Dekkers OM, Else T, et al. European Society of Endocrinology Clinical Practice Guidelines on the Management of Adrenocortical Carcinoma in Adults. European Journal of Endocrinology. 2018;179(4):G1–G46. https://pubmed.ncbi.nlm.nih.gov/30299884/
4. Lenders JWM, Duh QY, Eisenhofer G, et al. Pheochromocytoma and Paraganglioma: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism. 2014;99(6):1915–1942. https://academic.oup.com/jcem/article/99/6/1915/2537399