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HelpTest Code VMA Vanillylmandelic Acid, 24 Hour, Urine
Reporting Name
Vanillylmandelic Acid, 24 Hr, UUseful For
Screening children for catecholamine-secreting tumors with a 24-hour urine collection when requesting testing for only vanillylmandelic acid
Supporting a diagnosis of neuroblastoma
Monitoring patients with a treated neuroblastoma
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineAdvisory Information
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 that purpose include:
-PMET / Metanephrines, Fractionated, Free, Plasma
-METAF / Metanephrines, Fractionated, 24 Hour, Urine
-CATU / Catecholamine Fractionation, Free, 24 Hour, Urine
Necessary Information
1. Patients age is required.
2. Collection duration and urine volume are required.
3. All patients receiving L-dopa should be identified to the laboratory when this test is ordered.
4. 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 and during collection of specimen.
Supplies: Urine Tubes, 10 mL (T068)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a 24-hour urine specimen.
2. Add 25 mL of 50% acetic acid as preservative at the start of collection. If specimen is refrigerated during collection, preservative may be added up to 12 hours after collection. Use 15 mL of 50% acetic acid for children <5 years old. This preservative is intended to achieve a pH of between approximately 1 and 5. If necessary, adjust urine pH to 1 to 5 with 50% acetic or hydrochloric acid.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 180 days |
Special Instructions
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): <8.0 mg/24 hours
Day(s) and Time(s) Performed
Monday, Thursday; 8 a.m.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
84585
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| VMA | Vanillylmandelic Acid, 24 Hr, U | 43099-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 3580 | Vanillylmandelic Acid, Adult (>14y) | 3122-9 |
| 3581 | Vanillylmandelic Acid, Child (<15y) | 30571-4 |
| TM41 | Collection Duration | 13362-9 |
| VL39 | Urine Volume | 3167-4 |
Method Description
Vanillylmandelic acid (VMA) is measured by solid-phase extraction (SPE) of a 1-mL aliquot of urine. A known amount of stable-isotope labeled VMA internal standard (IS) is added to each urine specimen prior to SPE. VMA and IS are eluted from the SPE column with methanol. The methanol is evaporated and the VMA and IS are redissolved in liquid chromatography tandem-mass spectrometry (LC-MS/MS) mobile phase. A portion of this prepared extract is injected onto a LC column that separates VMA and IS from the bulk of any remaining specimen matrix. The VMA and IS are measured by mass spectrometry/tandem-mass spectrometry using the selected reaction monitoring mode. VMA is quantified using the ratio to IS versus urine calibrators.(Magera MJ, Thompson AL, Stoor AL, et al: Determination of vanillylmandelic acid in urine by stable isotope dilution and electrospray tandem mass spectrometry. Clin Chem. 2003;49:825-826; Eisenhofer G, Grebe S, Cheung NV: Monoamine-producing tumors. In Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 63)
Reject Due To
| All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.