Definition of Pheochromocytoma
A pheochromocytoma (fee-o-kroe-moe-sy-TOE-muh) is a rare, usually noncancerous (benign) tumor that develops in cells in the center of an adrenal gland. You have two adrenal glands, one above each kidney. Your adrenal glands produce hormones that give instructions to virtually every organ and tissue in your body.
If you have a pheochromocytoma, an adrenal gland releases hormones that cause persistent or episodic high blood pressure. If left untreated, a pheochromocytoma can result in severe or life-threatening damage to other body systems, especially the cardiovascular system.
Most people with a pheochromocytoma are between the ages of 20 and 50, but the tumor can develop at any age. Surgical treatment to remove a pheochromocytoma usually returns blood pressure to normal.
Symptoms of Pheochromocytoma
Signs and symptoms of pheochromocytomas often include:
- High blood pressure
- Rapid or forceful heartbeat
- Profound sweating
- Severe headache
- Paleness in the face
- Shortness of breath
Less common signs or symptoms may include:
- Anxiety or sense of doom
- Abdominal pain
- Weight loss
These signs and symptoms often occur in brief spells of 15 to 20 minutes. Spells can happen several times a day or less often. Your blood pressure may be within the normal range or remain elevated between spells.
Triggers of symptomatic spells
Spells may occur spontaneously or may be triggered by such factors as:
- Physical exertion
- Anxiety or stress
- Changes in body position
- Bowel movement
- Labor and delivery
Foods high in tyramine, a substance that affects blood pressure, also can trigger a spell. Tyramine is common in foods that are fermented, aged, pickled, cured, overripe or spoiled. These foods may include:
- Some cheeses
- Some beers and wines
- Dried or smoked meats
- Avocados, bananas and fava beans
- Pickled fish
- Sauerkraut or kimchi
Certain medications that can trigger a symptomatic spell include:
- Monoamine oxidase inhibitors (MAOIs), such as phenelzine (Nardil), tranylcypromine (Parnate) and isocarboxazid (Marplan)
- Stimulants, such as amphetamines or cocaine
When to see a doctor
The signs and symptoms of pheochromocytoma can be caused by a number of different conditions. Therefore, it’s important to get a prompt diagnosis.
Although high blood pressure is a primary sign of a pheochromocytoma, most people with high blood pressure don’t have an adrenal tumor. Talk to your doctor if any of the following factors are relevant to you:
- Difficulty controlling high blood pressure with current treatment plan
- A family history of pheochromocytoma
- A family history of a related genetic disorder: multiple endocrine neoplasia, type II (MEN II); von Hippel-Lindau disease; familial paraganglioma or neurofibromatosis 1 (NF1)
Researchers don’t know exactly what causes the development of a pheochromocytoma. They do understand that the tumor develops in specialized cells, called chromaffin cells, located in the center of an adrenal gland. These cells produce and release certain hormones, primarily adrenaline (epinephrine) and noradrenaline (norepinephrine).
The role of hormones
Adrenaline and noradrenaline are hormones that normally function as the trigger for your body’s fight-or-flight response to a perceived threat. The hormones prompt higher blood pressure, a faster heart rate and a boost in other body systems that enable you to react quickly with a burst of energy. A pheochromocytoma results in the irregular and excessive release of these hormones.
While most chromaffin cells reside in the adrenal glands, small clusters of these cells are also located in the heart, head, neck, bladder, back wall of the abdomen and along the spine. Tumors in these chromaffin cells, called paragangliomas, may result in the same effects on the body.
People with rare inherited disorders have an increased risk of developing a pheochromocytoma or paraganglioma, and tumors associated with these disorders are more likely to be cancerous. These genetic conditions include the following:
- Multiple endocrine neoplasia, type II (MEN II) is a disorder resulting in tumors in more than one part of the body’s hormone-producing (endocrine) system. The locations of other tumors associated with MEN II include the thyroid, parathyroid, lips, tongue and gastrointestinal tract.
- Von Hippel-Lindau disease can result in tumors at multiple sites, including the central nervous system, endocrine system, pancreas and kidneys.
- Neurofibromatosis 1 (NF1) results in multiple tumors in the skin (neurofibromas), pigmented skin spots and tumors of the optic nerve.
- Hereditary paraganglioma syndromes are inherited disorders that result in either pheochromocytomas or paragangliomas.
Complications of Pheochromocytoma
High blood pressure can damage multiple organs, particularly tissues of the cardiovascular system, brain and kidneys. If left untreated, high blood pressure associated with pheochromocytomas may result in a number of critical conditions, including:
- Heart disease
- Kidney failure
- Acute respiratory distress
- Damage to nerves of the eye
Cancerous (malignant) tumors
Rarely, a pheochromocytoma is cancerous (malignant), and the cancerous cells spread to other parts of the body (metastasize). Cancerous cells from a pheochromocytoma or paraganglioma most often migrate to the lymph system, bones, liver or lungs.
Preparing for your appointment
You’re likely to start by seeing your family doctor or a general practitioner. However, you may then be referred to a doctor who specializes in hormonal disorders (endocrinologist).
What you can do
Before your appointment, make a list that includes the following:
- Signs or symptoms — or any changes from normal— that may be causing concern
- A record of the frequency and duration of symptoms
- Recent changes or stresses in your life
- All medications — including over-the-counter drugs and dietary supplements — and doses you take
- A log of typical food and beverage consumption
- Family history of medical conditions
What to expect from your doctor
Your doctor will take a history of your symptoms and conduct a general medical examination. Questions that you should be prepared to discuss include the following:
- When did you begin experiencing symptoms?
- Have your symptoms been continuous or intermittent?
- Does anything seem to improve your symptoms?
- What, if anything, appears to bring on or worsen your symptoms?
- Are you taking medications for high blood pressure? Do you take the medication as prescribed?
- Have you been diagnosed with any other medical conditions? If so, do you follow the treatment plan for these?
Tests and diagnosis
Your doctor may order a number of tests.
Your doctor will likely order the following tests that measure levels of adrenaline, noradrenaline or byproducts of those hormones in your body:
- 24-hour urine test. You will be asked to collect a urine sample every time you urinate during a 24-hour period. Ask for written instructions about how to store, label and return the samples.
- Blood test. You will have blood drawn for laboratory work. Talk to your doctor about special preparations, such as fasting or skipping a medication. Do not skip a dose without specific instructions from your doctor.
If the results of laboratory tests indicate the possibility of a pheochromocytoma or paraganglioma, your doctor will order one or more imaging tests to locate a possible tumor. These tests may include:
- Computerized tomography (CT), a specialized X-ray technology
- Magnetic resonance imaging (MRI), a technology that uses radio waves and a magnetic field to produce detailed images
- M-iodobenzylguanidine (MIBG) imaging, a scanning technology that can detect tiny amounts of an injected radioactive compound that is taken up by certain tumors
- Positron emission tomography (PET), a scanning technology that can also detect radioactive compounds taken up by a tumor
A tumor in an adrenal gland may be discovered incidentally during imaging studies conducted for other reasons. In such cases, your doctor would order additional tests to determine the nature of the tumor.
Your doctor may recommend genetic tests to determine if a pheochromocytoma is related to an inherited disorder. Information about possible genetic factors can be important for a number of reasons:
- Because some inherited disorders can cause multiple conditions, test results may indicate the need to screen for other medical problems.
- Because some disorders are more likely to be recurrent or cancerous (malignant), your test results may affect treatment decisions or long-term plans to monitor your health.
- Results from your tests may indicate that other family members should be screened for pheochromocytoma or related conditions.
Ask your doctor about genetic counseling services that can help you understand the benefits and implications of genetic testing.
Treatments and drugs
The primary treatment for a pheochromocytoma is surgery to remove the tumor. Before you undergo surgery, your doctor will prescribe medications to stabilize your blood pressure and lower the risk of complications during surgery.
You will likely take two different drugs for a period of seven to 10 days that help lower blood pressure before surgery.
- Alpha blockers prevent noradrenaline from stimulating the muscles in the walls of smaller arteries and veins. Because these blood vessels remain open and relaxed, blood flow improves and blood pressure lessens. Examples of alpha blockers include phenoxybenzamine (Dibenzyline), doxazosin (Cardura), prazosin (Minipress) and terazosin (Hytrin). Side effects may include irregular heartbeat, dizziness, fatigue, vision problems, sexual dysfunction in men and swelling in your limbs.
- Beta blockers, which inhibit the effect of adrenaline, result in your heart beating more slowly and with less force. Beta blockers also help keep blood vessels open and relaxed by slowing the release of a particular enzyme from your kidneys. Examples of beta blockers include atenolol (Tenormin), metoprolol (Lopressor, Toprol) and propranolol (Inderal, Innopran). Side effects may include fatigue, upset stomach, headache, dizziness, constipation, diarrhea, irregular heartbeat, difficulty breathing and swelling in the limbs.
- Other medications that lower blood pressure may be prescribed if your blood pressure is not stabilized with alpha blockers and beta blockers.
In most cases, the entire adrenal gland with a pheochromocytoma is removed with laparoscopic, or minimally invasive, surgery. Your surgeon will make a few small openings through which he or she inserts wand-like devices equipped with video cameras and small tools.
The remaining healthy adrenal gland carries out the functions normally performed by two, and blood pressure usually returns to normal.
In some unusual situations, such as when the other adrenal gland has already been removed, a surgery may be considered to extract only the tumor and spare some of the healthy tissue.
If a tumor is cancerous (malignant), surgery may be effective only if the tumor and any metastasized tissues are isolated. However, even if all of the cancerous tissues are not removed, surgery may limit hormone production and provide some control of blood pressure.
As cancer is rare among cases of pheochromocytoma, the research about the best treatments is still relatively limited. Treatments for malignant tumors and metastasized cancer related to a pheochromocytoma may include the following:
- Radionuclide treatment. This radiation therapy combines MIBG, a compound that attaches to adrenal tumors, with a type of radioactive iodine. The treatment goal is to deliver radiation therapy to a specific site and kill cancerous cells.
- Chemotherapy. Chemotherapy is the use of powerful drugs that kill fast-growing cancer cells.
- Targeted cancer therapies. These medications inhibit the function of naturally occurring molecules that promote the growth and spread of cancerous cells.