What Is a Pheochromocytoma and What Are Its Symptoms?
A pheochromocytoma is a rare tumor that, in most cases, develops in the nerve tissue of the medulla of one of the two adrenal glands. These are two small endocrine glands located at the top of each kidney.
The adrenal glands help create and distribute important hormones, such as cortisol and adrenaline. They’re involved in the regulation of critical functions such as blood pressure, heart rate, immune response, metabolism, blood sugar, and stress.
Therefore, a pheochromocytoma can lead to many complex symptoms including high blood pressure. Also, in 10% of cases, it develops into cancer according to some studies. A small percentage of these tumors arise in other parts of the body, such as the heart, bladder, chest, neck, or the base of the skull.
Symptoms of a pheochromocytoma
Although the symptoms of pheochromocytomas vary from person to person, high blood pressure is present in 60% of cases. It may be constant or sporadic; in the latter case, it occurs in episodes lasting from a few seconds to several hours.
Other common symptoms of pheochromocytoma include the following:
- Excessive sweating
- Elevated heart rate
- Stomach pain and nausea
- Paleness and tremors
- Anxiety and a sense of doom
- High blood sugar levels
- Irritability and mood swings
- Weight loss
Some people have no symptoms at all. In fact, they may go their entire lives without knowing they have this tumor.
A pheochromocytoma can affect the functioning of the adrenal glands and this increases the risk of a complication known as an adrenergic crisis. This occurs when bursts of adrenal hormones enter the bloodstream.
This condition can lead to a life-threatening stroke or heart attack. Symptoms of an adrenergic crisis are a very rapid heart rate and fairly high blood pressure.
On the other hand, high blood pressure can cause damage to organs such as the kidneys, cardiovascular system tissues, and the brain. This, in turn, could lead to serious problems such as heart disease, kidney failure, blindness, or problems with the optic nerve.
It’s rare, but these tumors could also become malignant. The cancer cells can spread, most often to the lymphatic system, lungs, liver, or bones.
Causes and risk factors for a pheochromocytoma
Science doesn’t know the exact cause of pheochromocytoma formation. Up to 40% of cases are due to genetic factors according to some research. In these cases, the defective gene is inherited from either parent or is caused by a mutation of a gene in the affected person.
On the other hand, people with other inherited disorders have an increased risk of developing pheochromocytoma. In such cases, the tumor is more likely to become malignant. The associated genetic conditions are as follows:
- Multiple endocrine neoplasia type 2. This disorder creates tumors in the endocrine system.
- Von Hippel-Lindau disease. Another disorder that can lead to tumors in several parts of the body, including the adrenal glands.
- Neurofibromatosis 1. This creates tumors in the skin, pigmented skin spots, and tumors in the optic nerve.
- Hereditary paraganglioma syndromes. They can lead to pheochromocytoma or paraganglioma.
- Carney-Stratakis dyad. This consists of the presence of paraganglioma and gastrointestinal stromal tumors.
- Carney triad. This is when there are paragangliomas, gastrointestinal stromal tumors and pulmonary chondroma.
Researchers have established that, without being the causes of the disorder, some factors act as triggers for the symptoms. They are as follows:
- Intense physical activity or childbirth
- High levels of physical or emotional stress
- Consumption of tyramine, a substance found in aged or fermented foods, such as cheeses, wines or chocolate
- Some drugs
First of all, the physician should perform a thorough history and physical examination to establish suspicion of pheochromocytoma. To establish an accurate diagnosis, the physician may order several types of tests, such as the following.
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The goal is to measure the levels of hormones associated with the adrenal glands, such as adrenaline, noradrenaline or their by-products. Two types of tests are used for this purpose:
- 24-hour urine test. This consists of collecting a urine sample every time a person urinates in a 24-hour period.
- Blood test. Blood is drawn and analyzed in the laboratory in order to measure the levels of catecholamines.
2. Imaging tests
When laboratory tests suggest the presence of a pheochromocytoma, the physician will most likely ask for one or more imaging tests to detect the presence of the tumor and its location.
Typically, tests such as the following are used:
- Computerized tomography
- Magnetic resonance imaging
- M-iodobenzylguanidine (MIBG) imaging
- Positron emission tomography (PET)
The appearance of a pheochromocytoma is very distinctive. It’s possible that the tumor may be detected when imaging tests are carried out for other reasons. In such cases, the physician will ask for additional tests to determine the nature of the tumor.
3. Genetic tests
Such tests are performed to establish whether a pheochromocytoma is associated with a genetic abnormality. It’s important to determine if this is the case, as genetic disorders can cause many other conditions that should be detected.
There are also genetic conditions that increase the risk of developing a malignant tumor. Detecting them helps to design long-term plans to treat the health condition.
In addition, if a genetic problem is present, it’s best for other family members to undergo tests to see if they also have this abnormality or not.
Treatment of a pheochromocytoma
The first-line treatment for pheochromocytomas is surgery. Drugs are usually prescribed before the procedure to lower blood pressure to prevent a risky rise in blood pressure during the operation.
Such drugs are usually one or more of the following:
- Alpha-blockers. They relax and keep veins and arteries open so that blood flow improves, and blood pressure is reduced.
- Beta-blockers. They have the same effect as the previous ones and also make the heart beat more slowly and with less force. They’re prescribed after the use of alpha-blockers.
A diet rich in salt is usually recommended in order to prevent the pressure from dropping to a risky level. Most commonly, the entire adrenal gland and cancerous tissues, if present, are removed during surgery. The procedure is successful in 90% of cases.
If a pheochromocytoma is malignant and the cancer has spread, one of the following treatments may be used:
- Radiation therapy
- MIBG. This is radiotherapy that combines the use of a compound called MIBG with radioactive iodine
- Peptide receptor radionuclide therapy (PRRT)
- Targeted cancer therapies
Recovery and projection
Almost all patients who undergo surgery have improved blood pressure indices. When this doesn’t occur, hypertension should continue to be treated with drugs indicated for this purpose. If the pressure isn’t regulated, there’s a risk of serious complications.
It’s very important to closely monitor anyone who has had a pheochromocytoma. It’s rare, but the tumor can recur up to 15 years after surgery.
If there are risk factors, consult your doctor
People who have a genetic disorder associated with pheochromocytoma should talk to their doctor for proper follow-up, as well as those who have a family history of this problem.
It’s important to note that a malignant pheochromocytoma can’t be detected under the microscope. Also, early diagnosis doesn’t always improve the prognosis. The case should be seen by a highly trained specialist.It might interest you...
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