VANILLYLMANDELIC ACID (VMA), URINE 24HR
At the start of the 24 hour collection, discard first morning urine, from that time collect all urine for 24 hours. Urine must be kept refrigerated during collection. Record total volume of urine, mix well, then aliquot 25 mL to a screw top container. Indicate total volume of 24 hour urine on aliquot.
Alternate 24 hour urine collection with PRESERVATIVE:
Discard first morning urine. Collect urine for 24 hours with 25 mL 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. Indicate total volume on aliquot.
High Performance Liquid Chromatography
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.