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Test Code VMAR Vanillylmandelic Acid, Random, Urine

Reporting Name

Vanillylmandelic Acid, Random, U

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Ordering 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

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

Day(s) Performed

Monday through Friday

Test 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

Clinical Information

Vanillylmandelic acid (VMA) and other catecholamine metabolites (homovanillic acid [HVA] and dopamine) are typically elevated in patients with catecholamine-secreting tumors (eg, neuroblastoma, pheochromocytoma, and other neural crest tumors). VMA and HVA levels may also be useful in monitoring patients who have been treated as a result of one of the above-mentioned tumors.

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.

Report Available

3 to 5 days

Specimen Retention Time

7 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Disease States

  • Neuroblastoma

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.