VMA is excreted excessively in the urine. What may be the diagnosis?
High-Yield Explanation
VMA is the end product of catabolism of catecholamines. In phaeochromocytoma and neuroblastoma there is excessive synthesis of catecholamines which causes enhanced synthesis of VMA and its excretion in the urine. Also Know: VMA is the urinary product of both epinephrine and norepinephrine. It is a good screening test for pheochromocytoma, and is also used to diagnose and follow up neuroblastoma and ganglioneuroma. Ref: Gomella L.G., Haist S.A. (2007). Chapter 6. Laboratory Diagnosis: Urine Studies. In L.G. Gomella, S.A. Haist (Eds), Clinician's Pocket Reference: The Scut Monkey, 11e