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Test Name:
Vanillylmandelic Acid, Urine, 24-Hour
- SBMF No:
29160 - Performance Lab Name:
Manual Lab - Test Mnemonic:
VMA - ABN:
Not required - CPT Code:
82570; 84585 - LOINC Code:
3122-9; 30571-4; 9624-8 - Test Includes:
Vanilmandelic Acid (VMA)
Creatinine - Also Known As:
VMA - Spec Type:
Urine, 24-hour - Spec Container:
Plastic container with tightly fitting lid - Pref Vol:
10.0 mL aliquot from well-mixed collection
Note: Send urine aliquot with notation of 24-hour volume on aliquot label and on requisition - Min Vol:
4.0 mL aliquot from well-mixed collection - Fasting:
No - Spec Collect:
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 - Spec Process:
Upon completion of collection, mix entire specimen well and note 24-hour volume
Acidify urine sample with 6N Hydrochloric Acid to pH between 1.0 and 3.0 when received in lab
Pour 10.0 mL of urine into separate plastic container
Refrigerate urine aliquot and transport refrigerated
Send urine aliquot with notation of 24-hour urine volume on aliquot label and on requisition - Spec Store Transport:
Refrigerated - Spec Stability:
1 week refrigerated (2-8°C) - Spec Remarks:
Note: 24-hour urine is optimal specimen for testing - Methodology:
High Performance Liquid Chromatography (HPLC) - Use:
Diagnosis and follow-up of patients with pheochromocytoma and related neurogenic tumors - Clinical Significance:
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. - 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 - Additional Test Info:
Record total specimen volume, collection times, and pH [if required] on test requisition - Day Run:
Mon - Time Run:
7:00 am - Time Reported:
6:00 pm - Test Type:
HORMONE
