PHEOCHROMOCYTOMA.

A pheochromocytoma (Etymology: Greek "phaios =dark, chroma = color, kytos =cell, oma = tumor") or phaeochromocytoma (PCC) is aneuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth ^[1] and secretes high amounts of catecholamines, usually noradrenaline (norepinephrine), and adrenaline (epinephrine) to a lesser extent.^[2]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.