Incidentaloma of the adrenal gland

What is an incidentaloma of the adrenal gland?

The adrenal glands are small organs that belong to the endocrine glands and produce several vital hormones. We discover an incidentaloma by chance during an imaging examination of the abdomen. So we do not specifically search for a tumor, for example because patients have symptoms. The name is derived from the Latin word “incidere”, which means “to fall into”.

Incidentaloma is not a separate clinical picture or an independent diagnosis. Rather, the name refers to the randomness of the discovery. Incidentalomas can conceal various types of adrenal tumors – benign (most common) and malignant (less common).

Benign adenomas of the adrenal gland, which arise from glandular tissue, are the most common. As a rule, they are hormonally inactive, i.e. they do not produce any hormones. There are also adenomas that are hormone-active. For example, they release cortisol. Cysts (fluid-filled cavities) or lipomas (accumulation of fatty tissue) can also be incidentalomas. Incidentalomas are rarely malignant tumors, for example adrenal cancer or metastases.

In many cases, incidentalomas have no pathological value. In very few cases do the tumors cause symptoms and therefore usually go unnoticed. The diagnosis is made by chance, for example during an ultrasound examination or computer tomography, which takes place for another reason. A blood test allows more precise conclusions to be drawn about the type of tumor. For example, it shows whether or not it is releasing hormones.

Depending on the tumor, there are various treatment strategies: no treatment, observation and control or surgery. If surgery is necessary, it can usually be removed in a minimally invasive procedure (“keyhole surgery”).

Incidentaloma – frequency and age

Incidentalomas of the adrenal gland are among the most common tumors in humans. Experts estimate that around three percent of all adults around the age of 50 have a tumor in the adrenal gland. The risk of incidentaloma increases with age. In 80-year-olds, the frequency even rises to up to ten percent.

Approximately 80 percent of incidentalomas in the adrenal gland are benign, hormonally inactive tumors. This means that they do not produce hormones. These are usually adenomas that arise from glandular cells.

The other 20 percent include hormonally active Cushing’s and Conn’s adenomas as well as pheochromocytomas. Adrenal carcinomas or adrenal metastases also fall into this group. Adrenal cancer originates directly in the adrenal gland. Metastases in the adrenal glands, on the other hand, are caused by cancer of another organ in which metastases have formed in the adrenal gland. Examples are breast or lung cancer.

Incidentaloma: causes vary

Incidentaloma is not a disease in its own right, but the term refers to the circumstance of “accidental discovery”. Therefore, no general causes for the incidentaloma can be named. The term covers various tumors of the adrenal gland, which can have different consequences. Some examples:

• Hormone-inactive adenomas: The origin lies in the glandular tissue of the adrenal gland. They make up the majority of incidentalomas.
• Conn adenomas: The hormone-active tumor leads to Conn syndrome (hyperaldosteronism). This disease of the adrenal glands is associated with increased production of the hormone aldosterone.
• Cushing’s adenoma: A hormone-active tumor that leads to Cushing’s syndrome(hypercortisolism). In this disease, the production of the adrenal hormone cortisol is abnormally increased.
• Pheochromocytomas are tumors of the adrenal medulla that are usually hormonally active. For example, they produce adrenaline or noradrenaline. Most pheochromocytomas are benign, only rarely are they malignant
• Other benign tumors: originating from various tissues that do not produce hormones
• Adrenal carcinoma: cancer of the adrenal gland
• Adrenal metastases: Cancer metastases from another cancer such as breast cancer, lung cancer, renal cell cancer, lymphoma, malignant melanoma ( black skin cancer )

Symptoms: Incidentaloma often goes unnoticed

In many cases, an incidentaloma causes no symptoms and therefore goes unnoticed. The majority of incidentalomas are benign adenomas that are hormonally inactive and do not produce hormones. As a result, those affected have no symptoms due to increased hormone production and do not seek medical advice. The tumor is usually discovered by chance during an examination. Most incidentalomas are harmless and have no pathological value. However, as they grow and increase in size, they can cause discomfort and disrupt the function of the adrenal gland and neighboring organs.

Sometimes, however, incidentalomas are hormone-active and produce various messenger substances, for example adrenaline, noradrenaline, aldosterone or dopamine. Such hormone-active adrenal tumors can cause Cushing’s syndrome or Conn’s syndrome, for example. Incidentalomas then become noticeable due to the excess of hormones.

The symptoms depend on whether the tumor has developed from cells of the adrenal cortex or the adrenal medulla and which hormones are produced in increased quantities.

Conn’s adenoma: symptoms

Conn’s adenoma is a benign tumor of the adrenal cortex that is associated with an overproduction of the hormone aldosterone. This hormone plays an important role in regulating the water balance in the kidneys and increases blood pressure. Therefore, the following symptoms appear:

• High blood pressure that is permanently elevated and difficult to control
• Headache
• Dizziness
• Muscle weakness, muscle cramps
• strong feeling of thirst

Cushing’s adenoma: symptoms

Cushing’s adenoma is a mostly benign tumor in the adrenal cortex in which the production of the hormone cortisol is increased. This overproduction leads to Cushing’s syndrome, which manifests itself in a variety of symptoms. The most important are:

• Significant weight gain – the fat is particularly distributed on the abdomen and chest, but also on the face and neck
• Muscle breakdown – thin arms and legs
• Reddish stretch marks on the abdomen (comparable to “stretch marks”)
• Skin problems, acne
• High blood pressure
• Diabetes mellitus
• Strong body hair
• Bone loss(osteoporosis)
• psychological problems

Pheochromocytoma: symptoms

Pheochromocytoma is usually a benign tumor of the adrenal medulla in which the production of the stress hormones adrenaline and noradrenaline is uncontrollably increased. Possible symptoms are

• Permanently or suddenly elevated blood pressure – it can hardly be controlled with medication
• Headache
• Dizziness
• Sweating
• Palpitations, palpitations, cardiac arrhythmia
• Weight loss
• Trembling, nervousness, anxiety
• Diabetes mellitus

Adrenal cancer: symptoms

Adrenal cancer is a malignant tumor of the adrenal cortex (adrenocortical carcinoma). Symptoms can be caused by the growth of the tumor or by cancer metastasis elsewhere.

If the tumor is also hormone-active, it can trigger symptoms associated with the increased hormones. Examples are:

• Symptoms similar to Cushing’s syndrome
• in the production of sex hormones: strong body hair, hair loss, baldness, deep voice in women, growth of breasts in men

Incidentaloma: Diagnosis at the USZ

The diagnosis of “incidentaloma” is made by chance, for example during an ultrasound examination or computer tomography, which takes place for another reason. So we are not specifically looking for a tumor in the adrenal gland. Once the tumor has been discovered, we will ask you a few questions, for example:

• Do you have symptoms? If yes: Which ones? For example, heavy sweating, increased hair growth, palpitations
• How intense are the symptoms and when did they first occur?
• Do you have any known underlying diseases?
• Are you taking any medications? If yes: Which and since when?
• Have you had any previous abdominal imaging that could be used as a comparison?

This is followed by a physical examination, which includes palpation of the abdomen. We also pay attention to physical changes such as hair growth, fat distribution in the body or unusual breast growth in men. We also listen to the heart with a stethoscope and check the heartbeat. A blood pressure measurement shows whether the blood pressure values are elevated.

Incidentaloma: Hormone diagnostics

Then we try to find out whether the tumor is producing hormones or not. Elevated levels of certain hormones indicate that the adrenal tumor is producing hormones. The hormonal activity of the adrenal tumor can be determined by means of hormone determinations in the blood, from a urine sample or in saliva.

Hormone diagnostics are determined on an individual basis, but usually include

• Blood: sodium, potassium, aldosterone, ACTH, cortisol, DHEA, testosterone, androstenedione; dexamethasone inhibition test to rule out Cushing’s syndrome
• 24 h urine collection: determination of sodium, potassium and cortisol in unacidified 24 h urine; measurement of adrenaline, noradrenaline, metanephrine and normetanephrine (catecholamine degradation products) in acidified urine.
• Blood plasma: In the case of high blood pressure – determination of the aldosterone/renin quotient to rule out Conn syndrome.

Further examinations for incidentaloma

It is also important to differentiate between benign and malignant tumors. Imaging procedures such as:

• Computed tomography (CT) or magnetic resonance imaging (MRI = magnetic resonance imaging): These examinations provide detailed cross-sectional images of the adrenal gland and other organs. Fats in the adenoma can also be detected by means of density measurement. CT and MRI can reveal cancer or metastases.
• Positron emission tomography(PET) and/or scintigraphyThis provides information on the type of tumor, whether it is malignant or has spread elsewhere. The selection of this functional imaging depends on the preliminary examinations and the exact question.

We only rarely perform a biopsy (tissue removal), for example if there is a suspicion of metastases in the adrenal gland. Otherwise, it is not meaningful enough to distinguish a benign adenoma from a malignant carcinoma.

Incidentaloma: prevention, early detection, prognosis

Specific measures for the prevention and early detection of incidentaloma are not known. Rather, the tumor in the adrenal gland is discovered by chance during another examination, such as an ultrasound. In most cases, the incidentaloma has no pathological value and does not cause any symptoms.

In general, however, the advice is to have routine check-ups with your GP, which can reveal any existing high blood pressure, for example. It may be associated with an adrenal tumor. In addition, always seek medical advice if you have any complaints.

If you suffer from a cancer such as breast cancer or lung cancer, attend regular follow-up appointments. Possible metastases in the adrenal gland can also be detected during the close check-ups.

Course and prognosis of an incidentaloma

The course and prognosis of an incidentaloma cannot be generally predicted. Both depend initially on whether the incidentaloma is benign or malignant (rare). Most incidentalomas are benign. However, the adenomas can grow and impair the function of the kidney and neighboring organs. It also plays a role whether the tumor in the adrenal gland produces hormones (less frequently) or not, which is more often the case.

We remove hormone-producing incidentalomas. The course and prognosis of Cushing’s syndrome, for example, are good if the cause is eliminated – then it can be cured. Without treatment, however, it can be fatal within a few years.

The course and prognosis of Conn’s syndrome also depend on whether the cause can be eliminated. Conn’s syndrome is associated with high blood pressure that is difficult to regulate and can cause long-term damage to the cardiovascular system as well as the kidneys and eyes.

Incidentaloma: treatment depending on the tumor

The treatment of incidentaloma depends on various factors. First of all, it is important to determine whether the tumor is benign (usually harmless adenomas) or malignant (e.g. kidney carcinoma, metastases). It also plays a role whether the incidentaloma produces hormones or not. The aim of diagnostics is to find an individually tailored therapy that is appropriate for the person affected and their illness:

• The tumor is benign, does not produce hormones (hormone-inactive) and is smaller than four centimetres: No surgery or annual check-ups using radiological procedures (monitoring by imaging was previously recommended).
• The tumor is benign and secretes relevant amounts of hormones: Removal of the adrenal gland (adrenalectomy) together with the tumor as part of a laparoscopy. This is a minimally invasive procedure (“keyhole surgery”) that requires only small incisions and is therefore gentler.
• Unclear tumors that have not been operated on: Check by CT or MRI after six to twelve months. If the tumor grows by more than 20 percent, surgery is recommended. We only check the course of the hormones in special cases.
• It is suspected that the tumor is malignant, but there is no evidence of metastases: Smaller tumors under six centimetres can be removed by laparoscopy. However, if there are indications that the tumor has grown beyond the organ, open surgery is the treatment of choice.