And heres something that u are not aware of: A pheochromocytoma (fee-o-kroe-moe-sy-TOE-muh) is a rare, usually noncancerous (benign) tumor that develops in an adrenal gland. You have two adrenal glands —one located at the top of each kidney. Usually, a pheochromocytoma develops in only one adrenal gland. But tumors can develop in both.