Vanillylmandelic Acid (VMA), Random Urine
Also known as: 3-Methoxy-4-Hydroxymandelic Acid, VMA, Random Urine
Use
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.
Special Instructions
Use for patients where 24-hour urine collection is difficult, such as pediatric patients. A 24-hour urine collection is preferable (see Vanillylmandelic Acid (VMA), 24-Hour Urine [004143]). Patients should avoid salicylates, caffeine, phenothiazine, and antihypertension agents, as well as coffee, tea, chocolate, fruit (especially bananas), and any vanilla-containing substances for 72 hours prior to collection.
Limitations
The test is developed by LabCorp and its performance characteristics are determined by the company. It has not been cleared or approved by the FDA. Some neuroblastoma patients show VMA abnormalities but do not excrete increased levels of VMA. Additionally, 20%-32% of neuroblastoma patients do not exhibit elevated VMA, although they may have other laboratory abnormalities such as increased metanephrines, homovanillic acid (HVA), or dopamine.
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 2161-8
- 3124-5
- 9624-8
- 2161-8
- 9624-8
- 3124-5
Result Turnaround Time
4-7 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL aliquot
Minimum Volume
1 mL aliquot
Container
Plastic urine container
Collection Instructions
If specimen is to be stored for longer than seven days before analysis, use random urine transport tube.
Patient Preparation
Patient should avoid salicylates, caffeine, phenothiazine, and antihypertension agents. Also avoid coffee, tea, chocolate, fruit (especially bananas), and any vanilla-containing substances for 72 hours prior to collection.
Storage Instructions
Vanillylmandelic acid is stable at room temperature unpreserved for seven days.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |