What is the pheochromocytoma and what is the paraganglioma?

Pheochromocytoma is a rare, but potentially life-threatening, tumor of the adrenal medulla (in the inner layer of the adrenal gland) producing increased amounts of catecholamines (the hormones of stress), while paragangliomas are tumors of the paraganglia.


What are the Paraganglia?

Paraganglia are called clusters of neuroendocrine cells (similar to adrenal medullary cells), which migrate during intrauterine life, in various parts of the body, from head to pelvis, carrying elements from either the sympathetic or parasympathetic nervous system. They constitute “stations” along the path of nerve signals between the brain and periphery, aiming at better coordination of the information. The adrenal medulla, in essence, is a large sympathetic paraganglion and so both pheochromocytomas and sympathetic paragangliomas have a common origin and therefore share common characteristics.


How common are the pheochromocytoma and paraganglioma?

The incidence of pheochromocytoma and paraganglioma together is about 0.8 per 100,000 people per year. However, autopsies series suggest that the actual number is higher between 1:6500 and 1:2500, as the majority of patients are diagnosed postmortem.


At what age do pheochromocytoma and paraganglioma occur?

They can occur at any age, with peak age in the 5th-6th decade of life, but in the case of genetic syndromes, tumors appear much earlier.


What are the causes of pheochromocytoma and paraganglioma?

These tumors are mostly sporadic, but 40% of them are inherited through genetic mutations.


Are these tumors cancer?

These tumors can be malignant at a rate of 10-17%.


What are the symptoms and signs of these tumors?

Pheochromocytoma is called “the great mimic” as it can occur with the symptoms of any disease:

  • 61% of these tumors at autopsies occurred in patients who were known to have had hypertension
  • but 91% had the non-specific symptoms associated with pheochromocytoma /paraganglioma
  • In more than 1/3 of patients, death precedes diagnosis.

Classical symptomatology includes paroxysms of:

  • Tachycardia
  • Headache
  • sweating and
  • arterial hypertension

Paroxysms can be triggered by a simple movement such as bending over, by eating foods containing tyramine, such as chocolate and bananas, and by taking certain drugs such as antidepressants, as well as by surgical manipulations during a surgery.


How are pheochromocytoma and paraganglioma diagnosed?

The diagnosis of these tumors is made by measuring metanephrines, which are derivatives of the metabolism of catecholamines in the blood, and tumor-(s) and possible metastases are located by imaging scans, such as computed or magnetic resonance imaging, adrenal scintigraphy (I-MIBG), positron emission tomography (PET) and somatostatin receptor scintigraphy (octreoscan). Genetic testing excludes or confirms genetic familial disease.


How are the pheochromocytoma and paraganglioma treated?

The treatment of choice is adrenalectomy, after pharmaceutical preparation (blockade) of the patient to avoid triggering a hypertensive crisis. In the case of relapses, metastases or paragangliomas that their removal endangers vital organs/tissues, a combination of surgery, pharmacotherapy, radiation, chemotherapy, I-MIBG, transarterial chemoembolization can be used. Long-term follow-up of patients post-surgery is necessary, both to treat cardiovascular morbidity/mortality, and to timely detect a possible metastatic disease.