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Paediatric Laboratory Medicine

Vanillylmandelic Acid (VMA), Urine

Clinical Significance

The measurement of VMA and HVA are crucial for the diagnosis and follow up of patients with neuroblastoma, pheochromocytoma and related tumors. Neuroblastoma is the most common solid malignancy of infancy with an occurrence rate of approximately one in every 7000 children under the age of 5. The tumors develop in utero and are present, though usually undetectable, at birth. Neuroblastomas arise in organs that develop from the embryonal neural crest. The tumors have morphological and biochemical features common to certain tissues of that lineage -- the sympathetic nervous system ganglia and the adrenal medulla. Abdominal neuroblastomas arise principally in the adrenal gland and extend into the retroperitoneal region. They may be revealed by the presence of a mass during routine examination by the pediatrician. The posterior mediastinum is a common site of tumors arising from paravertebral sympathetic ganglia. A variety of biochemical and genetic tests have been developed for routine clinical use. Neuroblastoma cells possess the metabolic pathways for the synthesis of catecholamines, and approximately 90% of tumors secrete elevated levels of catecholamines. Urinary HVA, the principal metabolite of dopamine, and urinary VMA, the principal metabolite of epinephrine and norepinephrine, have been measured in patients with neuroblastoma and proven to be valuable both in diagnosis and for monitoring therapy. The prognosis of patients with neuroblastoma is directly correlated with the patient's age and the stage of tumor spread at diagnosis. Children less than 1 year at diagnosis have a survival rate of 82%; those between 1 and 2 years have 32% and it drops to only 10% if diagnosis is made beyond 2 years of age. A VMA/HVA ratio greater than 1.5 is considered favorable in the prognosis

Test Name

Vanillylmandelic Acid (VMA), Urine

Test Code

VMAU

Division

Biochemistry - Biochemistry

Method

LC-MS/MS

Turn Around Time

Weekly

Specimen Type

Urine

Minimum Specimen Requirements

20 mL

Storage/Transportation

Frozen

Approval is not required

CPT Codes

84585

Shipping and Contact Information

The Hospital for Sick Children
Rapid Response Laboratory
170 Elizabeth Street, Room 3642
Toronto, ON
M5G 2G3
Canada
Phone: 416-813-7200
Phone: 1-855-381-3212

Reference Range

Spot or Random Urine:
≤1y : ≤11.0 mmol/mol cre
2-4y : ≤ 6.5 mmol/mol cre
5-9y : ≤ 5.0 mmol/mol cre
10-19y : ≤ 5.0 mmol/mol cre
≥20y : ≤3.5 mmol/mol cre

Timed Urine:
≤1y : ≤12.0 µmol/d
2-4y : ≤15.0 µmol/d
5-9y : ≤18.0 µmol/d
10-19y : ≤30.0 µmol/d
≥20y : ≤34.0 µmol/d