Homovanillic Acid (HVA), 24-Hour Urine

Diagnose neuroblastoma, ganglioneuroblastoma, and pheochromocytoma; follow course of tumor treatment. This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

HVA is the major terminal metabolite of the dopamine pathway. VMA is the major terminal metabolite of the norepinephrine pathway. HVA is often excreted in excess amounts by neuroblastomas, ganglioneuroblastomas, pheochromocytomas, and in Riley-Day syndrome. Excretion may be intermittent. Plasma HVA is increased in schizotypal personality disorders. Approximately 20% of subjects with neuroblastoma do not have increased VMA.

Patient should avoid aspirin, disulfiram, reserpine, and pyridoxine, if possible, at least 48 hours prior to collection of the specimen. Levodopa should be avoided for two weeks before collection.