<prompt> Most common site for pheochromocytoma is?Adrenal medullaAdrenal cortexParavertebral ganglionParaaortic-sympathetic chain  <response>: 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. 