Homovanillic Acid, Random, Urine
Use
Measurement of urinary homovanillic acid (HVA) is used to screen children for catecholamine‑secreting tumors, including neuroblastoma, pheochromocytoma, and other neural crest tumors, and to monitor treatment of neuroblastoma. It is also useful for diagnosing inborn errors of catecholamine metabolism such as monoamine oxidase‑A deficiency (which causes decreased urinary HVA) or dopamine beta‑hydroxylase deficiency (which causes elevated urinary HVA). Administration of L‑dopa and Bactrim may interfere with test results and should be discontinued or noted at the time of collection.
Special Instructions
Patient’s age is required. Patients receiving L‑dopa should be identified when ordering, and L‑dopa should be discontinued for 24 hours prior to collection. Patients taking Bactrim should be identified at time of collection. If not ordering electronically, complete and send an Oncology Test Request (T729).
Limitations
Elevated urinary HVA may reflect dopamine beta‑hydroxylase deficiency, catecholamine‑secreting tumors, or L‑dopa administration; decreased values may suggest monoamine oxidase‑A deficiency. A positive result requires confirmatory testing, and a normal result does not exclude a catecholamine‑secreting tumor.
New York Approved
Methodology
Mass Spectrometry (LC‑MS/MS)
Biomarkers
LOINC Codes
- 11146-8
- 11146-8
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
Clean, plastic urine collection container; submission into plastic, 10‑mL urine tube
Collection Instructions
Collect a random urine specimen; adjust urine pH to between 1 and 5 by adding 50% acetic acid or hydrochloric acid dropwise and checking pH
Patient Preparation
Discontinue L‑dopa for 24 hours prior to collection; note Bactrim use
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 28 days |
| Frozen | 180 days |