Pheochromocytoma

What is a pheochromocytoma?

A pheochromocytoma is a rare type of tumor. Most of them are benign (noncancerous). It arises from specific cells called chromaffin cells; these create hormones that are necessary for normal bodily functions. Most pheochromocytomas appear in the adrenal glands, which are located above the kidneys in the back of the upper abdomen. About 90 percent of pheochromocytomas occur in the adrenal medulla, the adrenal gland’s inner layer and the location of most chromaffin cells. The 10 percent of tumors that occur outside of this area are called extra-adrenal pheochromocytomas or paragangliomas. Paragangliomas can be found in the chest, heart, neck, and bladder. Pheochromocytomas are rare tumors, only occurring in less than 1 percent of people with high blood pressure. Since many individuals with these tumors go undiagnosed, the true incidence of pheochromocytomas are unknown. They affect males and females equally, and can affect people of all ages. They most commonly occur in people between 30 and 50 years old.

What are the symptoms of a pheochromocytoma?

In some cases, individuals may not develop symptoms. Those who do may experience sudden episodes that involve these symptoms:

• High blood pressure (hypertension)
• Heart palpitations
• Excessive sweating
• Headaches
• Dizziness
• Fatigue
• Paleness

Less common symptoms include, but are not limited to:

• Pain in the chest or abdomen
• Vomiting
• Diarrhea or constipation
• Weakness
• Anxiety attacks

What causes a pheochromocytoma?

In most cases, pheochromocytomas happen randomly, for unknown reasons. About 25 to 35 percent of cases may be due to an inherited autosomal dominant trait, meaning that the genes received from a parent were mutated. Since it is a dominant trait, only a single copy of the mutated gene is needed for the disease to appear. Symptoms occur because of the release of certain hormones called catecholamines. Chromaffin cells release them. Chromaffin cells are a part of the sympathetic nervous system, which is what controls certain involuntary activities in the body. The release of those excessive hormones causes high blood pressure and other symptoms, including the pheochromocytoma itself.

How is a pheochromocytoma diagnosed?

A pheochromocytoma is diagnosed using the following procedures:

• Examination of patient’s and patient’s family’s medical history
• Imaging tests: X-rays, MRIs, M-iodobenzylguanidine (MIBG) imaging, and/or Positron emission tomography (PET)
• Twenty-four-hour urine test
• Blood test
• Genetic testing

What are the treatments for a pheochromocytoma?

Pheochromocytoma treatment includes, but is not limited to:

• Removal by surgery
• Medications for stabilizing blood pressure
• Genetic counseling

Where can I find out more about pheochromocytomas?

• National Organization for Rare Disorders (NORD)
• Mayo Clinic
• Genetics and Rare Diseases Information Center