Vanillylmandelic Acid (VMA), 24 Hr Urine (VMA)

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Test Code: VMASO

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Synonyms/Keywords

Vanillylmandelic Acid

3-Methoxy-4-Hydroxymandelic Acid
4-Hydroxy-3-Methoxymandelic Acid
VMA
Neuroblastoma Profile

Vanillylmandelic Acid 24h(VMA)

Vanillylmandelic Acid, 24 Hour, Urine

24 VMASO

Useful 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

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)	Pediatric Minimum Volume (no repeat)
No	Urine	Urine Plastic Container		5 mL	2 mL

Collection Processing Instructions

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.

Collection Instructions:

1. Collect a 24-hour urine specimen.

2. Collection duration and urine volume are required.

3. Patient’s age is required.

4. 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 less than 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 HCI acid.

Additional Information:

All patients receiving L-dopa should be identified to the laboratory when this test is ordered.

Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when this test is ordered.

Specimen Stability Information

Specimen Type	Temperature	Time
Urine	Refrigerate (preferred)	28 days
Urine	Frozen	180 days

Interference

Values are more commonly elevated during a hypertensive episode.

Values may be normal in some individuals with pheochromocytoma.

All patients taking Bactrim should be identified to the laboratory when VMA and HVA tests are ordered due to potential interference.

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Report Available	Methodology/Instrumentation
Mayo Clinic Laboratories	Monday through Friday	3-5 days	Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reference Lab

Mayo Clinic Laboratories

Test 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 1 of the above-mentioned tumors.

Reference Range Information

Performing Location	Reference Range
Mayo Clinic Laboratories	<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 > or =15 years (adults): <8.0 mg/24 hours

Interpretation

Vanillylmandelic acid and/or homovanillic acid concentrations are elevated in most patients (more than 90%) 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 values are suggestive of a pheochromocytoma, but they are not diagnostic

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
84585		1

Classification