Vanillylmandelic Acid (VMA), Spot or random, urine

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 for patients with neuroblastoma depends upon numerous prognostic factors, risk stratification, disease spread, and treatment. The long-term survival rates for patients with low, intermediate and high risk disease are nearly 100%, >90%, and 50%, respectively.  A VMA/HVA ratio greater than 1.5 is considered favorable in the prognosis.