OVERVIEW

What is a paraganglioma?

A paraganglioma is a type of neuroendocrine tumor. Most patients with paragangliomas are asymptomatic, while symptomatic patients exhibit different manifestations depending on the tumor's location and whether it secretes catecholamines. Currently, clinical "cure" can be achieved through surgery, radiotherapy, or chemotherapy, but complete eradication is difficult.

Paragangliomas can be classified into sympathetic paragangliomas, which secrete catecholamines (causing constriction of small arteries and veins, elevated blood pressure, and increased heart rate), and parasympathetic paragangliomas, which are non-secretory.

Is a paraganglioma benign or malignant?

The vast majority of paragangliomas are benign and asymptomatic, with only about 15%–35% being malignant.

What is the difference between a paraganglioma and a pheochromocytoma?

Broadly speaking, a paraganglioma refers to any tumor occurring in the paraganglia. However, another well-known condition—pheochromocytoma—can also arise in the paraganglia.

Therefore, some consider pheochromocytomas to include paragangliomas, while others believe paragangliomas encompass both pheochromocytomas and non-pheochromocytoma paragangliomas.

Since 90% of pheochromocytomas occur in the adrenal glands, the World Health Organization (WHO) has established a distinction: "pheochromocytoma" refers only to tumors within the adrenal glands, while "paraganglioma" refers exclusively to tumors in paraganglia outside the adrenal glands.

Are paragangliomas common?

They are relatively rare, though the exact incidence is unknown. Among them, non-functional parasympathetic paragangliomas have an incidence of approximately (0.2–1.0) per 100,000 people.

SYMPTOMS

What are the manifestations of paraganglioma?

In general, most paragangliomas often have no obvious symptoms or may even be asymptomatic.

However, clinical manifestations vary depending on their location and whether they secrete catecholamines.

• If the paraganglioma occurs in the neck or skull base, symptoms such as hoarseness, difficulty breathing, coughing, and chest or back pain may appear.

• If the paraganglioma occurs in the bladder, symptoms such as urinary obstruction, syncope during urination, and hematuria may occur.

• If catecholamines are secreted, symptoms similar to those of pheochromocytoma may appear, including paroxysmal hypertension, palpitations, dizziness, and excessive sweating. Less common symptoms may include orthostatic hypotension (dizziness or vertigo when changing from lying or sitting to standing), blurred vision, weight loss, polyuria, constipation, and hyperglycemia.

CAUSES

What causes paraganglioma?

The exact cause is currently unknown. According to existing research, some cases are inherited through family genetics, while others occur without any family history of the disease.

Among patients with hereditary paraganglioma, most are associated with mutations in genes encoding the SDH enzyme complex, with SDHD being the most commonly mutated gene. The inheritance pattern is autosomal dominant.

Is paraganglioma hereditary?

It can be. The inheritance pattern is autosomal dominant, meaning if one parent has the disease, each child has about a 50% chance of inheriting it.

However, even if a mutated gene is inherited, environmental or other factors may prevent the disease from manifesting.

Is paraganglioma contagious?

No.

DIAGNOSIS

How is paraganglioma diagnosed?

It can be confirmed through imaging and biochemical tests.

What tests are needed for paraganglioma?

Biochemical tests: Similar to pheochromocytoma, the test measures the level of vanillylmandelic acid (VMA), a catecholamine metabolite, in 24-hour urine. However, since paragangliomas may not secrete catecholamines or secrete them in small amounts, misdiagnosis is possible.

Imaging tests: Such as CT, MRI, PET, and radionuclide imaging, used to locate the tumor. If necessary, a contrast agent may be injected during CT (similar to an injection into the blood vessels). The contrast agent may cause allergies or kidney damage, but the incidence is low, and doctors will take precautions, so there is no need to worry excessively. Different imaging tests have varying focuses, each with its advantages, complementing one another.

Which diseases are easily confused with paraganglioma? How to differentiate them?

It mainly needs to be distinguished from pheochromocytoma. One difference is the tumor location, and another is that paragangliomas rarely secrete catecholamines.

TREATMENT

Which department should I see for paraganglioma?

Endocrinology or oncology.

Is it necessary to go to the hospital for paraganglioma?

Yes.

How is paraganglioma treated?

Mainly surgical resection and radiotherapy.

• For catecholamine-secreting paragangliomas below the neck, surgical removal is generally considered.

• For tumors at the skull base or neck, observation may be recommended first, followed by radiotherapy or surgery depending on tumor growth or progression.

Does paraganglioma require hospitalization?

Hospitalization is needed for surgery or radiotherapy. If observation is recommended after diagnosis, regular outpatient follow-ups are sufficient without hospitalization.

Can paraganglioma be cured?

Yes. However, recurrence may occur after surgery, and radiotherapy cannot completely eliminate the tumor—it only controls progression to achieve clinical "cure," not true "radical cure."

DIET & LIFESTYLE

What should patients with paraganglioma pay attention to in their diet?

Patients with catecholamine-secreting paragangliomas may experience paroxysmal hypertension, so they should follow a low-salt, low-fat diet, quit smoking and alcohol, and avoid spicy or stimulating foods.

For asymptomatic paraganglioma patients, there are no specific dietary restrictions—maintaining a healthy and balanced diet is sufficient.

What should patients with paraganglioma pay attention to in daily life?

Patients with catecholamine-secreting paragangliomas may experience paroxysmal hypertension and should manage their emotions carefully in daily life.

They may also develop orthostatic hypotension, so it’s important to change positions (e.g., from squatting to standing or sitting to standing) slowly and avoid sudden or large movements.

Do paragangliomas require follow-up? How?

Yes.

Initially after diagnosis, follow-ups are typically scheduled every 2 weeks or 3 months based on the doctor’s treatment plan. Once the condition stabilizes, follow-ups can be extended to every 6 months to 1 year. Follow-up tests include imaging studies and blood/urine sample collection.

Do paragangliomas affect fertility?

No. However, there is a possibility of genetic transmission to offspring. Patients planning to conceive should consult a genetic specialist to assess the risk of the disease in their children.

PREVENTION

Can paraganglioma be prevented? How to prevent it?

There is currently no effective prevention method. Early detection and treatment are the only options. However, since paraganglioma often has mild or no symptoms, regular health check-ups are recommended, and medical attention should be sought promptly if any issues are found.