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HelpTest Code LAB0290221 Vanillylmandelic Acid, Random, Urine
Additional Codes
| Mayo Test ID |
|---|
| VMAR |
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Screening children for catecholamine-secreting tumors using a random urine collection when requesting vanillylmandelic acid only
Supporting a diagnosis of neuroblastoma
Monitoring patients with a treated neuroblastoma
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Vanillylmandelic Acid, Random, USpecimen Type
UrineOrdering Guidance
In the past, this test has been used to screen for pheochromocytoma. However, vanillylmandelic acid (VMA) is not the analyte of choice to rule out a diagnosis of pheochromocytoma. Recommended tests for this purpose are:
-PMET / Metanephrines, Fractionated, Free, Plasma
-METAF / Metanephrines, Fractionated, 24 Hour, Urine
-CATU / Catecholamine Fractionation, Free, 24 Hour, Urine
Necessary Information
1. Patient's age is required.
2. All patients receiving L-dopa should be identified to the laboratory when this test is ordered.
3. Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when this test is ordered.
Specimen Required
Patient Preparation: Administration of L-dopa may falsely increase vanillylmandelic acid results; it should be discontinued 24 hours prior to specimen collection.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. Adjust the random urine pH to a level between 1 and 5 by adding 50% acetic acid or hydrochloric acid dropwise and checking the pH.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 180 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
<1 year: <25.0 mg/g creatinine
1 year: <22.5 mg/g creatinine
2-4 years: <16.0 mg/g creatinine
5-9 years: <12.0 mg/g creatinine
10-14 years: <8.0 mg/g creatinine
≥15 years (adults): <7.0 mg/g creatinine
Interpretation
Vanillylmandelic acid (VMA) and/or homovanillic acid concentrations are elevated in more than 90% of patients with neuroblastoma; both tests should be performed. A positive test could be due to a genetic or nongenetic condition. Additional confirmatory testing is required.
A normal result does not exclude the presence of a catecholamine-secreting tumor.
Elevated VMA values are suggestive of a pheochromocytoma, but they are not diagnostic.
Day(s) Performed
Monday through Friday
Report Available
3 to 5 daysSpecimen Retention Time
7 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84585
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| VMAR | Vanillylmandelic Acid, Random, U | 3124-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 60274 | Vanillylmandelic Acid, Random, U | 3124-5 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.