Laboratory Services

Vanillylmandelic Acid, 24 Hour, Urine

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Updated Test Information:

Test Description
Vanillylmandelic Acid, 24 Hour, Urine

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

Test ID
General Information

Useful for:

  • Screening children for catecholamine-secreting tumors with a 24-hour urine collection when requesting testing for only vanillylmandelic acid

    • Vanillylmandelic acid (VMA) and other catecholamine metabolites such as homovanillic acid (HVA) measurement in urine are used for screening children for catecholamine-secreting tumors such as neuroblastoma and other neural crest tumors and monitoring those who have had treatment for these tumors

  • Supporting a diagnosis of neuroblastoma

    • More than 90% of individuals with neuroblastoma have elevated VMA and/or HVA

  • Monitoring patients with a treated neuroblastoma

Specimen Type

24-Hour Urine

Specimen 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

  • Supplies: Urine Tubes, 10 mL

  • Specimen Volume: 5 mL

  • Collection Instructions:

    • Collect a 24-hour urine specimen

    • 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

    • If necessary, adjust urine pH to 1 to 5 with 50% acetic or hydrochloric acid

  • Additional Information: See Collection and Transportation for 24-Hour Urine Specimens

Minimum Sample Volume

2 mL


  • Refrigerated (preferred): 28 days

  • Frozen: 180 days

Unacceptable Specimen Conditions

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


  • VMA is not the analyte of choice for diagnosis of pheochromocytoma, which is better detected by testing for metanephrines

  • Treatment with L-dopa can impact test results and should be discontinued 24 hours prior to collection

  • Bactrim can impact test results and should be noted at time of collection

  • Values are more commonly elevated during a hypertensive episode

  • Values may be normal in some individuals with pheochromocytoma


Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Estimated TAT

2-4 days

Testing Schedule



7 days

CPT Code(s)


Reference Range
Age (years) Reference Values (mg/g creatinine)
< 1 < 25.0
1 < 22.5
2 - 4 < 16.0
5 - 9 < 12.0
10 - 14 < 8.0
≥ 15 < 8.0 mg/24 hours
Performing Lab


LOINC Code(s)

3122-9, 30571-4, 13362-9, 3167-4

Additional Information