Vanillylmandelic Acid, Random, Urine
Use
Screening children for catecholamine‑secreting tumors when requesting vanillylmandelic acid only; supporting diagnosis of neuroblastoma; monitoring treated neuroblastoma patients. Over 90% of individuals with neuroblastoma have elevated VMA or HVA—but VMA is not the analyte of choice for pheochromocytoma, for which metanephrines are better. L‑dopa and Bactrim may influence results and should be managed appropriately prior to collection.
Special Instructions
Discontinue L‑dopa 24 hours before collection; record Bactrim at time of collection. Patient age is required on request. If not ordered electronically, include Oncology Test Request (T729) form.
Limitations
A positive result does not confirm tumor—additional testing needed. A normal result doesn't exclude a catecholamine‑secreting tumor. Elevated VMA is suggestive but not diagnostic of pheochromocytoma. VMA is less suitable than metanephrines for pheochromocytoma detection.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 3124-5
- 3124-5
Result Turnaround Time
7 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
2 mL
Container
Plastic, 10‑mL urine tube (submission); clean plastic urine collection container (collection)
Collection Instructions
Collect a random urine specimen; adjust pH between 1 and 5 by adding 50% acetic acid or hydrochloric acid dropwise.
Patient Preparation
Discontinue L‑dopa 24 hours prior; Bactrim use should be noted.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 28 days (preferred) |
| Frozen | 180 days |