Vanillylmandelic Acid, 24 Hour, Urine

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

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

24-Hour Urine

• 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

2 mL

• Refrigerated (preferred): 28 days


• Frozen: 180 days

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)

2-4 days

Monday-Friday

7 days

84585

Mayo

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

Test Definition: VMA

Collection and Transportation for 24-Hour Urine Specimens