<prompt> All of the following are increased in pheochromocytomas. exceptVinyl Mandelic Acid VMAMetanephrines5HIAACatecholamines  <response>: Answer is C 5HIAA: SHIAA levels are elevated in carcinoid syndrome and not in pheochromocytoma. Pheochromocytomas and paragangliomas Pheochromocytomas and paragangliomas synthesize and store catecholamines which include norepinephrine noradrenaline, epinephrine adrenaline and dopamine Pheochromocytomas are typically associated with elevated levels of plasma and urinary catecholamines and their metabolites such as VMA and metanephrines The most sensitive test for diagnosis ofpheachromocytomas is measurement of fractionated metanephrines in urine and free metanephrine in plasma. 