All of the following are increased in pheochromocytomas. except
High-Yield Explanation
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.