what is a vma

Vanillylmandelic acid (VMA) is a chemical intermediate in the synthesis of artificial vanilla flavorings and is an end-stage metabolite of the catecholamines (dopamine, epinephrine, and norepinephrine) . It is produced via intermediary metabolites. VMA is found in the urine, along with other catecholamine metabolites, including homovanillic acid (HVA), metanephrine, and normetanephrine. The VMA test measures the amount of VMA that is passed into the urine, typically over a 24-hour period, to detect excess epinephrine and norepinephrine. It is used to detect tumors called neuroblastomas and other neuroendocrine tumors. The VMA test is primarily used to detect and rule out tumors called neuroblastomas in children with an abdominal mass or other symptoms suggestive of the disease. It may be ordered along with an homovanillic acid (HVA) test to help diagnose a neuroblastoma, to monitor the effectiveness of treatment, and to monitor for neuroblastoma recurrence.