Vanillylmandelic Acid (VMA), 24 hour Urine (VMA)
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| Synonyms:
| VMA, 3-Methoxy-4-Hydroxymandelic Acid |
| Specimen: | Urine; 24-hour urine collection in a 24-hour container.
Patient should be instructed how to collect a 24-hour urine. |
| Volume: | 30 mL aliquot |
| Minimum Volume: | 1 mL |
| Collection: | Submit a 30 mL urine aliquot for testing with documentation of 24 hour volume.
Vanillylmandelic acid is stable at room temperature (15-30°C) unpreserved for up to 5 days. Use 6N HCl to preserve specimens stored for longer than 5 days before analysis.
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| Rejection Criteria: | Unpreservative specimen greater than 5 days old; boric acid collection; specimen not kept chilled; pH not 1-3; improper labeling. |
| Reference Range: | 1.8 - 6.7 mg/24 hours |
| Methodology: | High-pressure liquid chromatography (HPLC) |
| Test Use: | Diagnose pheochromocytoma. Follow up of neuroblastoma, ganglioneuroma, and ganglio neuroblastoma. This test can have 20-30% false negatives for neuroblastoma. Evaluate hypertension. |
| Additional Information: | Instructions for 24-hour urine collection are available from lab. Patient should avoid salicylates, caffeine, phenothiazine, antihypertensives, tea, coffee, fruit - especially bananas, and vanilla for 72 hours before collection. |
| Testing Includes: | Specimen sent to LabCorp. LabCorp test # 004143. |
| Testing Facility: | LabCorp |