Use

Measurement of urinary homovanillic acid (HVA) is used to screen children for catecholamine‑secreting tumors, including neuroblastoma, pheochromocytoma, and other neural crest tumors, and to monitor treatment of neuroblastoma. It is also useful for diagnosing inborn errors of catecholamine metabolism such as monoamine oxidase‑A deficiency (which causes decreased urinary HVA) or dopamine beta‑hydroxylase deficiency (which causes elevated urinary HVA). Administration of L‑dopa and Bactrim may interfere with test results and should be discontinued or noted at the time of collection.