VANILLYLMANDELIC ACID (VMA), URINE 24HR
Collect 24 hour urine (instructions below). Send 10.0mL acidified urine refrigerated in a screw-capped plastic urine cup. Record total volume on test requisitiion and specimen label.
Collect urine with 25mL of 6N HCl at start of collection to maintain pH between 1 and 3. Refrigerate urine during collection (critical). Mix the collection well before removing aliquot.
Without preservative, urine aliquot must be sent frozen. Total 24hr urine volume is required for testing.
With preservative: Room temperature: 10 days Refrigerated: 14 days Frozen: 1 year. Without preservative: Room temperature: Unacceptable Refrigerated: 7 days Frozen: 14 days
2-4 days Setup Mon, Wed, Fri
Diagnose pheochromocytoma, VMA is of value for evaluation of hypertension, diagnose and follow up neuroblastoma, ganglioneuroma, and ganglioneuroblastoma. Most neuroblastoma patients excrete excess HVA in 24-hour collections. If VMA and HVA are both used in workup, up to 80% of all cases will be detected.