Vanillylmandelic acid measurement in the urine is used mainly in the investigation of children for catecholamine-secreting tumors, in the investigation of arterial hypertension, and in the diagnosis and monitoring of neuroblastoma, ganglioneuroma, and ganglioneuroblastoma.
Vanillylmandelic acid (VMA) is the end product of the metabolism of epinephrine (adrenaline) and norepinephrine (noradrenaline) and is excreted in the urine. Concentrations of vanillylmandelic acid and homovanillic acid are elevated in most neuroblastoma patients (more than 90%).
Possible Interpretations of Pathological Values
- Increase: Intense stress, strenuous exercise, ganglioneuroblastoma, ganglioneuroma, hypertension, neuroblastoma, pheochromocytoma. Medications: aspirin, aminosalicylic acid, epinephrine, levodopa, lithium carbonate, mephenesin, methocarbamol, nalidixic acid, norepinephrine, oxytetracycline, penicillin, phenazopyridine, salicylates, sulfobromophthalein, sulfonamides. Some herbal remedies and coffee.
- Decrease: Familial dysautonomia (Riley-Day syndrome). Medications: chlorpromazine, clofibrate, clonidine, guanethidine analogs, imipramine, levodopa, methyldopa, monoamine oxidase (MAO) inhibitors, reserpine, salicylates.
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.