In Pheochromocytoma, which of the following is increased in urine?
High-Yield Explanation
a. VMA(Ref: Nelson's 20/e p 2227-2729, Ghai 8/e p 525)Biochemical tests for Pheochromocytoma:Pheochromocytomas synthesize and store catecholamine, so elevated plasma and urinary levels of catecholamines methylated metabolites (VMA or vanillyl mandelic acid), metanephrines, are the cornerstone for the diagnosisAmong these tests, the fractionated metanephrines and catecholamines are the most sensitive.QIn contrast to adults with pheochromocytoma in whom both norepinephrine and epinephrine are elevated, children with pheochromocytoma predominantly excrete norepinephrine in the urine.