Researchers don't know exactly what causes the development of a pheochromocytoma. They do understand that the tumor develops in specialized cells, called chromaffin cells, located in the center of an adrenal gland. These cells produce and release certain hormones, primarily adrenaline (epinephrine) and noradrenaline (norepinephrine).
The role of hormones
Adrenaline and noradrenaline are hormones that normally function as the trigger for your body's fight-or- flight response to a perceived threat. The hormones prompt higher blood pressure, a faster heart rate and a boost in other body systems that enable you to react quickly with a burst of energy. A pheochromocytoma results in the irregular and excessive release of these hormones.
While most chromaffin cells reside in the adrenal glands, small clusters of these cells are also located in the heart, head, neck, bladder, back wall of the abdomen and along the spine. Tumors in these chromaffin cells, called paragangliomas, may result in the same effects on the body.