Pheo Para Primer

What is pheochromocytoma/paraganglioma?

Pheochromocytomas and paragangliomas are neuroendocrine tumors (NETs), meaning they develop from cells located throughout the body that behave like both neurons (are electrically active) and endocrine cells (make hormones). Like other NETs, they can be “functional” — meaning they produce hormones which can cause an array of health problems — or “non-functional” —meaning they don’t produce hormones. Pheochromocytomas and paragangliomas often develop as part of an inherited syndrome and have been called “the most heritable tumor in man.”

Pheochromocytoma (pheo) is the name given to these tumors when they develop in the adrenal gland, though this term is used by some for a tumor of this type found anywhere in the abdominal cavity. Tumors which form in the adrenal gland, or in another location within the trunk of the body, are more likely to be “functional.”

Paraganglioma (para) is the general term for tumors of this type that occur in any location. Tumors not located in the adrenal gland can form anywhere in the body, often on or near blood vessels like the jugular vein, the carotid artery, or the abdominal aorta.

What symptoms do pheo/para cause?

Although Pheo/para are most known for the symptoms they can cause, many of these tumors do not cause any noticeable symptoms and are found incidentally during imaging studies performed for unrelated reasons. When tumors are functional, they cause symptoms easily explained by other, more common health conditions. Symptoms caused by pheo/para include

  • High or fluctuating blood pressure
  • Headaches
  • Profuse sweating
  • Flushing
  • Palpitations / pounding or racing heart
  • A feeling of impending doom
  • Intense, unexplained feelings of anxiety or rage
  • Pain.

How is pheo/para diagnosed?

Patients presenting with symptoms suggestive of pheo/para, or who have a suspicious mass, will usually receive blood (and sometimes urine) tests. Further, more specific, imaging may be performed. Biopsies are not usually performed on pheo/para, and are generally considered to be risky when dealing with these tumors.

What causes pheo/para?

As with many cancers, the answer to what causes pheo/para is complex. Some occur without an apparent underlying inherited mutation, and are referred to as sporadic tumors. Others form as the result of a genetic mutation inherited from a parent. Patients diagnosed with pheo/para should be aware of the implications their diagnosis might have for their families:

  • The high degree of heritability in these tumors has led to the recommendation that everyone diagnosed with pheochromocytoma/paraganglioma should receive genetic testing
  • Overall, current research indicates that about ~40-50% of these tumors occur as the result of an inherited mutation
  • Extra-adrenal tumors are more likely to be associated with an inherited syndrome that carries a greater risk of metastases
  • Inherited mutations in more than 12 different genes have been shown to predispose families to developing pheo/para
  • Carrying a mutation does not mean you or your family members will definitely develop a tumor, or metastatic disease.

Can children develop pheo/para?

Yes, pheo/para have been found in children as young as 7 years of age  It is important to know that functional tumors may cause different symptoms in children. For example, instead of high-blood pressure, children may develop signs of Attention Deficit Hyperactive Disorder (ADHD). Some children will express more generalized behavioral problems. Bed-wetting which resolves after treatment has also been reported.

How is pheo/para treated?

Surgical removal of the tumor(s) is preferred, when possible. When the tumor or tumors can’t be removed surgically, there are other treatment options available, some of which are listed below:

Please note that treatment choices for individual patients are dependent on a variety of factors unique to each person. Options, and expected outcomes, should be discussed with the patient’s medical team.

Where can pheo/para patients and their families find information and support?

There are many organizations which offer information on pheochromocytoma an paraganglioma, general advice and support, and which connect patients with clinicians.



NorCal CarciNET


Pheochromocytoma Support Foundation

Pheo Para Alliance

Pheo Para Project

SDHB Pheo Para Coalition

Unicorn Foundation

VHL Alliance