Most common site for pheochromocytoma is?

Ans. is 'a' i.e., Adrenal medulla * Pheochromacytomas arise in adrenal medulla (not in adrenal cortex) and at extra-adrenal sites along sympathetic chain.* Most pheochromocytomas arise in adrenal medulla* Pheochromocytomas are catecholamine secreting tumors arising from chromaffin cells.* About 10% of these tumors arise at extra-adrenal sites, where they are called paragangliomas. These extra- adrenal sites area) Along the para-aortic sympathetic chain.b) Organ of Zuckerkandl (paravertebral ganglion).c) Along the sympathetic chain in neck and mediastinum.d) In the wall of urinary bladder.