The MOST sensitive 24 hour urinary biochemical test to suggest pheochromocytoma among the following is: (A) Vanillylmandelic acid, (B) Fractionated metanephrines, (C) Total metanephrines, (D) Catecholamines
Answer is B. Table 343-2 Biochemical Tests Used for Pheochromocytoma Diagnosis Diagnostic Method Sensitivity Specificity 24-h urinary tests Vanillylmandelic acid ++ ++++ Catecholamines +++ +++ Fractionated metanephrines ++++ ++ Total metanephrines +++ ++++ Ref: Harrisons Principles of Internal Medicine, 18th Edition, Page 2963