This page was reviewed under our medical and editorial policy by
Gagandeep Singh, MD, Liver and Pancreatic Surgeon, City of Hope | Duarte
This page was reviewed on June 9, 2023.
Paragangliomas are a rare tumor type—they occur in about two out of every 1 million people, according to the National Cancer Institute (NCI). They tend to develop between the ages of 30 and 50, although they sometimes appear in children.
A paraganglioma is a type of neuroendocrine tumor made of chromaffin cells, which produce hormones for the nervous system and release them into the blood. They are normally present in the adrenal glands and in clumps around nerve cells (ganglia).
Hormones are essential to everyday life. They regulate breathing, metabolism, heart rate and other bodily functions. But when tumors secrete hormones, they can have effects throughout the body that are far greater than other tumors.
Paragangliomas typically start out as benign (not cancerous) tumors, but they may cause symptoms that may become life-threatening. Benign paragangliomas may also become cancerous later and spread to other parts of the body (a process called metastasis).
Paragangliomas may develop in the adrenal glands that sit on top of the kidneys (they’re called pheochromocytomas in this case) or outside of the adrenal glands (which is when they’re called paragangliomas).
Paragangliomas, also known as extra-adrenal pheochromocytomas, may be found all over the body, typically in the head, neck and torso.
Paragangliomas release hormones that activate the body’s fight-or-flight response. Called catecholamines, these hormones are usually released in response to stress. A paraganglioma can release these hormones at will, sometimes in large doses.
These hormones may lead to symptoms that include:
These symptoms may feel like a panic or anxiety attack.
These attacks, if they become severe, can cause a catecholamine crisis, which may result in a heart attack, stroke or severe high blood pressure.
Not all paragangliomas release hormones, meaning some are asymptomatic. Those that develop in the head and neck usually don’t release hormones, but if they grow big enough, they can obstruct swallowing, cause coughing or lead to hearing loss.
Other symptoms of paragangliomas may include:
Some cases of paragangliomas are linked to genetics. These types of tumors are associated with some hereditary syndromes, including:
Mutations in more than 20 genes have been identified that may lead to an increased risk for developing pheochromocytomas and paragangliomas, according to the NCI.
If the patient's paraganglioma isn’t associated with a hereditary syndrome, it’s considered nonsyndromic. Nonsyndromic paragangliomas are more common in women than in men.
If the paraganglioma is spreading to other parts of the body, it’s known as metastatic paraganglioma. About 35 percent to 50 percent of paragangliomas may spread to other parts of the body, according to the NCI.
In about 10 percent of cases, paragangliomas have already spread by the time they’re diagnosed, according to Seminars in Oncology. Metastasis is more likely for paragangliomas that are discovered outside of the adrenal glands and for those that are larger than 5 centimeters (cm).
The care team uses multiple lab tests to detect the presence of paragangliomas. These tests will look for:
The care team may use imaging tests to determine where the tumors are in the body and if the patient is a candidate for removing them surgically. They may order magnetic resonance imaging (MRI), a computed tomography (CT) scan or a positron emission tomography (PET) scan. They may also turn to specialized imaging that uses certain compounds to help highlight hidden paragangliomas.
They’ll likely recommend genetic testing to determine whether the patient has hereditary syndromes associated with paragangliomas. This can alert the care team to other symptoms and tumors to monitor. It may also lead to discussions with relatives about getting tested and any monitoring that may be recommended for them.
Depending on the features of the patient's paraganglioma, the care team may suggest several different treatment options. If the paraganglioma is causing symptoms, they may be controlled with medications. For example, the doctor may prescribe alpha-blockers and beta-blockers to treat high blood pressure.
If the symptoms could become life-threatening, the care team is likely to suggest surgery to remove the tumor. Surgery can be risky because these tumors release hormones. If hormones get released during surgery, it could lead to complications. Usually, a strict medical regimen is implemented in the days and weeks leading up to surgery day to help prevent complications.
If surgery is successful, it should resolve the symptoms. If the tumor can’t be safely removed, radiation therapy may be used to help shrink it and relieve symptoms.
If the paraganglioma is not causing symptoms, the care team may recommend a “watch-and-wait” approach. Many paragangliomas grow very slowly, so doctors will check regularly to ensure that the patient's condition hasn’t changed drastically. This is called watchful waiting.
A paraganglioma that has turned cancerous and metastasized is a challenge. Treatment options are limited. The care team may try to treat metastatic paragangliomas by removing metastases surgically, giving chemotherapy to fight cancer, or using targeted radiotherapies to treat the paragangliomas.
A newer technique for paraganglioma care involves the use of theranostics. This technology pairs diagnostic biomarkers with therapeutic agents to identify and target cancer cells for destruction.
The Food and Drug Administration has approved a drug called AzedraⓇ (I131-iobenguane/MIBG) to treat patients 12 years and older who’ve been diagnosed with local, advanced or metastatic pheochromocytomas and paragangliomas.
After treatment for a paraganglioma, the patient will likely need yearly testing to check for elevated hormone levels from a cancer recurrence.