Pheochromocytoma: symptoms and therapy of the adrenal tumor

The pheochromocytoma is a hormone-producing tumour usually found in the adrenal medulla and can manifest itself through symptoms such as high blood pressure, headaches, sweating and tachycardia. The diagnosis is made by determining several laboratory values ​​and additional imaging procedures. The focus of therapy is the surgical removal of the tumour. The pheochromocytoma is non-cancerous primarily (benign) and has a good prognosis, especially if diagnosed early.

What is a pheochromocytoma?

A pheochromocytoma is a tumour that mainly produces the hormones adrenaline and noradrenaline, so-called catecholamines, and is located in most cases (85 to 90 per cent) in the adrenal medulla.

The tumour occurs in paraganglia in rarer cases (10 to 15 per cent). These are structures that produce hormones and originate from the peripheral nervous system. These can then be found in the abdomen or chest area in the so-called sympathetic trunk. This is a series of nerve nodes of the sympathetic nervous system running next to the spine. This form of pheochromocytoma is known as extra-adrenal pheochromocytoma or paraganglioma.

Malignant tumours (cancerous growths) can also produce the catecholamine dopamine.

The tumours can also occur on both sides, for example, in both adrenal glands or paraganglia on both sides of the body. This mainly affects children or occurs in the context of hereditary tumours. In children, a third of the tumours are extra-adrenal, i.e. outside the adrenal glands.

 

Causes and frequency of pheochromocytoma

Around two to eight people per million inhabitants fall ill annually – the tumour is comparatively rare. Adults between the ages of 30 and 50 are particularly affected.

About 20 per cent of pheochromocytomas are malignant, i.e. malignant. This primarily affects tumours outside the adrenal medulla, large tumours, those affected at a young age, and the female sex. Malignant tumours can also metastasize, primarily to the skeletal system, liver, and lymph nodes. Other organs that may be affected are the central nervous system, the pleura (pleura) and the kidneys.

Hereditary forms of the tumour

A smaller proportion, about 25 per cent, is an inherited form of the tumour. Those affected tend to get sick earlier, at under 40. These tumours occur as part of various inherited clinical pictures, such as neurofibromatosis or von Hippel-Lindau syndrome. Both are hereditary diseases or diseases based on genetic defects, particularly evident through skin and nervous system symptoms.

A pheochromocytoma can also form in multiple endocrine neoplasia (MEN) type II context. This is a hereditary syndrome, i.e. a clinical picture whose primary manifestation is tumours of the thyroid gland; in addition, an overactive parathyroid gland can also occur. In addition, a hereditary pheochromocytoma can occur as a familial paraganglioma or in the form of other gene mutations.

 

What are the symptoms of pheochromocytoma?

The following symptoms can occur as a result of the uncontrolled release of adrenaline and noradrenaline into the bloodstream and their effect on various organs in the body:

• High blood pressure (hypertension): paroxysmal or permanently increased
• tachycardia and palpitations
• headache
• Sweat
• Tremble
• Nervousness to anxiety and panic attacks
• weight loss
• nausea
• weakness
• paleness

Pain in the area of ​​the adrenal gland, i.e. in the flank region, is usually not one of the typical symptoms of an adrenal gland tumour, but it can occur. If other organs are also displaced due to the size of the tumour, this can also lead to pain.

In addition, diabetes mellitus can develop over time as a result of the excessive production of catecholamines.

How do you diagnose a pheochromocytoma?

For example, various tests can be carried out if a pheochromocytoma is suspected due to typical symptoms or family history. The diagnosis includes laboratory controls and imaging procedures.

But which blood values ​​are determined in pheochromocytoma? Various laboratory values ​​can be examined as part of the laboratory control:

• Determination of the breakdown products of adrenaline and noradrenaline (metanephrine and normetanephrine) im
  • blood plasma
  • Urine (24-hour urine collection)
• Failure to reduce adrenaline and noradrenaline levels in the blood after administration of clonidine ( clonidine is a drug used to lower blood pressure)

If laboratory tests have confirmed the suspicion of pheochromocytoma and the diagnosis has been established, imaging should be performed to localize the ulcer precisely. Sonography (ultrasound), computed tomography (CT), magnetic resonance imaging (MRT) and scintigraphic display methods are available for this purpose.

Genetic diagnostics should also be carried out if a pheochromocytoma is present. This can then be followed by screening for other tumours. In addition, in the case of family stress, regular check-ups should be carried out for family members.

How is a pheochromocytoma treated?

To treat pheochromocytoma, the tumour should be surgically removed. For this purpose, a drug to inhibit the effects of nor and adrenaline – a so-called alpha-blocker – is given before the operation since the tumour can release large amounts of hormones during the operation. Beta-blockers should only be administered in combination, for example, with an alpha blocker, as this can otherwise lead to critically high blood pressure values.

If the tumour cannot be surgically removed, symptom control is the focus of therapy. Drugs to inhibit the effects of the hormones can also be given here.

Measures to reduce tumour size are also available. In addition to surgical procedures, this includes administering chemotherapeutic agents and radiotherapy. Here, 131 J MIBG therapy can be carried out in the context of 123 J MIBG-positive metastases. MIBG is the abbreviation for the substance meta-iodo-benzylguanidine. This is marked with radioactive iodine-131. For the therapy, the radioactive substance is injected via the vein, after which absorption in the tumour tissue results in local irradiation. The response rate is 25 percent.

 

Prognosis and life expectancy in pheochromocytoma

If a benign tumour is diagnosed early, the prognosis is good. After the removal of the tumour, the blood pressure returns to normal in more than half of the cases, and the remaining symptoms usually disappear. Throughout the disease, about 15 per cent of those affected develop a recurrence, i.e. a recurrence of the tumour, so check-ups should be carried out.

Suppose the benign tumour is only discovered late. In that case, consequential damage may have already developed that can affect life expectancy, such as damage to the cardiovascular system due to permanently elevated blood pressure.

In the case of malignant degeneration of the tumour, the mean survival time after surgical treatment is about 5.5 years. In principle, the time the tumour is discovered is also essential here. The survival rate five years after diagnosis is 35 to 60 per cent.