VANILMANDELIC ACID, RANDOM UR
- Code
- 900.5600
- Name
- VANILMANDELIC ACID, RANDOM UR
- Category
- None
- Department
- Send-Out
- Start Date
- Expiration Date
- Synonyms
- VMA
- CPT Codes
- 84585, 82570
- Site
- SBMF
- Reference Test
- 29260
Specimen Information
- Type
Urine, Random
- Volume
10.0 ml
- Transport Info
Acidify urine sample with 6N Hydrochloric Acid to pH between 1.0 and 3.0 when received in lab (Approx. 1.0 mL of 6 N HCl for every 100.0 mL of urine)
Refrigerated- Fasting Required?
- False
- Patient Instructions
Routine random urine collection
IMPORTANT: Refrigerate after collection and through transportation to prevent bacterial growth
Note: 24-hour urine is optimal specimen for testing, refer to Vanilmandelic Acid (VMA), 24-Hour Urine- Reference Range
0.0-6.0 mg/g creatinine
- 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.