Vanillylmandelic Acid (VMA), Random Urine

Pediatric testing for the evaluation of hypertension; diagnose and follow up neuroblastoma, ganglioneuroma, and ganglioneuroblastoma. Most neuroblastoma patients excrete excess HVA in 24-hour collections. If VMA and HVA are both used in work-up, up to 80% of all cases will be detected.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Some neuroblastoma patients are positive for urinary homovanillic acid abnormality but do not excrete increased VMA. Twenty percent to 32% of patients with neuroblastoma do not have elevation of VMA. Many will have other laboratory abnormalities such as increased metanephrines, homovanillic acid (HVA), or dopamine.

1. Soldin SJ, Hill JG. Liquid chromatographic analysis for urinary 4-hydroxy-3-methoxymandelic acid and 4-hydroxy-3-mehoozyphenylacetic acid and Its use in investigation of neural crest tumors. Clin Chem. 1981; 27(3):502-503. PubMed 7471405

Bio-Rad VMA. Package insert. October 1989.

Kaplan LA, Pesce AJ. Clinical Chemistry, Theory, Analysis, and Correlation. St Louis, Mo: CV Mosby Co;1989.

Patient should avoid salicylates, caffeine, phenothiazine, and antihypertension agents. Also coffee, tea, chocolate, fruit (especially bananas and any vanilla-containing substances for 72 hours prior to collection).