Test Details
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Result Turnaround Time
4 - 7 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.
Test Includes
Creatinine, urine; VMA, urine (mg/L); VMA:creatinine ratio
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 (eg, pediatric patients). Twenty-four-hour urine collection is preferable (see Vanillylmandelic Acid (VMA), 24-Hour Urine [004143]).
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.
Custom 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.
Specimen Requirements
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.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 7 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
Pediatric patients1 and adults: VMA:creatinine ratio
• Up to 2 years: 0.0−18.8 mg/g creatinine
• 2 to 4 years: 0.0−11.0 mg/g creatinine
• 5 to 9 years: 0.0−8.3 mg/g creatinine
• 10 to 19 years: 0.0−8.2 mg/g creatinine
• Older than 19 years: 0.0−6.0 mg/g creatinine
Storage Instructions
Vanillylmandelic acid is stable at room temperature unpreserved for seven days.
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).
References
Footnotes
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 123208 | VMA, Random Urine | 070016 | Creatinine, Random U | mg/dL | 2161-8 | |
| 123208 | VMA, Random Urine | 123209 | VMA, Random Urine | mg/L | 9624-8 | |
| 123208 | VMA, Random Urine | 070050 | VMA/Crt, Random U | mg/g Creat | 3124-5 | |
| Order Code | 123208 | |||||
| Order Code Name | VMA, Random Urine | |||||
| Order Loinc | ||||||
| Result Code | 070016 | |||||
| Result Code Name | Creatinine, Random U | |||||
| UofM | mg/dL | |||||
| Result LOINC | 2161-8 | |||||
| Order Code | 123208 | |||||
| Order Code Name | VMA, Random Urine | |||||
| Order Loinc | ||||||
| Result Code | 123209 | |||||
| Result Code Name | VMA, Random Urine | |||||
| UofM | mg/L | |||||
| Result LOINC | 9624-8 | |||||
| Order Code | 123208 | |||||
| Order Code Name | VMA, Random Urine | |||||
| Order Loinc | ||||||
| Result Code | 070050 | |||||
| Result Code Name | VMA/Crt, Random U | |||||
| UofM | mg/g Creat | |||||
| Result LOINC | 3124-5 |