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For hours, walk-ins and appointments.Synonyms
- 3-Methoxy-4-Hydroxymandelic Acid, 24-Hour Urine
- VMA, 24-Hour Urine
Special Instructions
Record total 24-hour urine volume on the request form.
Expected Turnaround Time
3 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Information
Related Documents
For more information, please view the literature below.
Specimen Requirements
Specimen
Urine (24-hour)
Volume
4 mL aliquot
Minimum Volume
1 mL aliquot (Note: This volume does not allow for repeat testing.)
Container
Plastic urine container, no preservative (preferred), or acidic preservative
Collection
Instruct the patient to void at 8 AM and discard the specimen. Then collect all urine, including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning). Measure and record total urine volume. Mix well; send aliquot. Label container with patient's name, date and time collection started, and date and time collection completed.
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 |
Freeze/thaw cycles | Stable x3 |
Patient Preparation
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).
Test Details
Use
Diagnose pheochromocytoma, VMA is of value for 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.
Limitations
This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Reference Interval
0.0−7.5 mg/24 hours
Additional Information
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.
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 004143 | Vanillylmandelic Acid, 24-Hr U | 3122-9 | 004144 | VMA, Urine | mg/L | 9624-8 |
| 004143 | Vanillylmandelic Acid, 24-Hr U | 3122-9 | 004145 | VMA, Urine, 24hr | mg/24 hr | 3122-9 |
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