The tumor likely originates from the adrenal medulla or embryological
remnants of neural crest cells. Such a tumor produces the adrenal medullary hormone
epinephrine or its precursor norepinephrine. Both of these compounds are sympathetic
agonists and cause effects similar to those seen by activation of the sympathetic
nervous system. This would include sweating, flushing, increased heart rate and blood
pressure, and a decrease in GI motility. These compounds can also act as neurotransmitters
in the brain and affect mood and behavior. Transient increases in both
systolic and diastolic blood pressure are seen during bouts of increased hormone
secretion by this tumor. These episodes are often induced by increased abdominal
pressure or stress. Sudden increases in blood pressure can result in severe headaches.
This type of tumor is known as a pheochromocytoma. In more than 70% of cases,
surgical removal of the tumor results in a return of blood pressure to normal and elimination
of the "attacks".