Pheochromocytoma overview

Overview
A pheochromocytoma (phaeochromocytoma outside of the US) is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells) or extra-adrenal chromaffin tissue which failed to involute after birth, which secretes excessive amounts of catecholamines, usually epinephrine and norepinephrine. Extra-adrenal paragangliomas (often described as extra-adrenal pheochromocytomas) are closely related, though less common, tumors that originate in the ganglia of the sympathetic nervous system and are named based upon the primary anatomical site of origin.

Traditionally it is known as the "10% tumor":
 * bilateral disease is present in approximately 10% of patients
 * approximately 10% of tumours are malignant
 * approximately 10% are located in chromaffin tissue outside of the adrenal gland
 * Approximately 10% arise in childhood
 * Approximately 10% are familial
 * Approximately 10% recur after being resected
 * Approximately 10% patients do not have hypertension (Campbell's Urology)