VANILMANDELIC ACID, 24 HOUR URINE

Code
900.0915
Name
VANILMANDELIC ACID, 24 HOUR URINE
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
CPT Codes
84585, 82570
Site
SBMF
Reference Test
29160
ATLAS Test Code

Specimen Information

Type

Urine, 24 Hour

Volume

10.0 mL aliquot from well-mixed collection
Note: Send urine aliquot with notation of 24-hour volume on aliquot label and on requisition

Transport Info

Refrigerated

Fasting Required?
False
Patient Instructions

To begin collection of timed specimen, have patient urinate, noting date and exact time
Discard this first portion of urine, but document date and time of voiding on container label and test requisition as "start" of timed specimen
Save all urine voided during designated time period, including portion voided at exact end of time period
IMPORTANT: Refrigerate entire specimen (2-8°C) during and after collection to prevent bacterial growth
Document date and time of final voiding on label and requisition as "end" of timed specimen

Reference Range

0-1 year: 0-18.8 mg/g creatinine or 0-2.3 mg/day
2-4 years: 0-11.0 mg/g creatinine or 0-3.0 mg/day
5-9 years: 0-8.3 mg/g creatinine or 0-3.5 mg/day
10-19 years: 0-8.2 mg/g creatinine or 0-6.0 mg/day
Greater than 19 years: 0-6.0 mg/g creatinine or 0-6.8 mg/day

Methodology

High Performance Liquid Chromatography (HPLC)

Clinical Significance

Diagnosis and follow-up of patients with pheochromocytoma and related neurogenic tumors
Quantitation of the acidic metabolites of catecholamines has been valuable in the diagnosis and follow-up of patients with pheochromocytoma and related neurogenic tumors. It has been found that approximately one in every 500 hypertensive patients may have this type of tumor. Vanilmandelic acid (VMA) or 4-hydroxy-3-methoxymandelic acid (HMMA) is the end product of both epinephrine (adrenaline) and norepinephrine (noradrenaline) metabolism. Measurement of urinary VMA is commonly used as a diagnostic tool because VMA is present in larger amounts than other catechol metabolites and it is stable in acidified solutions. Since catecholamine-secreting tumors are surgically curable, patients with clinical features that suggest adrenergic excess, particularly those with severe hypertension and patients from families with history of multiple endocrine neoplasia syndromes should be tested. Urinary VMA measurements can be used to screen for pheochromocytoma, but they are considered less sensitive although more specific than urinary metanephrine measurements. It is also used to follow patients with neuroblastoma.

Back