<prompt> Which among the following is the most common site of ectopic phaeochromocytoma?Organ of ZuckerkandlBladderFilum terminaleCeliac plexus  <response>: Almost all pheochromocytomas about 90 occur in the abdomen, and most of these 85 are in the adrenal medulla. Extra-adrenal pheochromocytomas including sympathetic and parasympathetic paragangliomas are found in the perirenal area, the organ of Zuckerkandl, the urinary bladder, the hea, the neck, and the posterior mediastinum. Extra-adrenal pheochromocytomas account for 10 of all pheochromocytomas in adults and 30-40 of pheochromocytomas in children. They are usually larger than adrenal pheochromocytomas. Ref: Else T., Hammer G.D., McPhee S.J. 2010. Chapter 12. Disorders of the Adrenal Medulla. In S.J. McPhee, G.D. Hammer Eds, Pathophysiology of Disease, 6e. 