In suspected neuroblastoma, which urinary metabolite would be elevated?

In suspected neuroblastoma, which urinary metabolite would be elevated?

• A. Increased blood dopamine levels
• B. Increased blood epinephrine levels
• C. Increased urinary homovanillic acid
• D. Decreased urinary vanillylmandelic acid

Answer: (C)

Neuroblastoma often produces catecholamines, which are broken down into metabolites that are excreted in urine. The main urinary metabolites used in this context are homovanillic acid (HVA) and vanillylmandelic acid (VMA). When the tumor is active, dopamine metabolism increases, leading to elevated HVA in the urine. This makes urinary HVA a reliable marker for suspected neuroblastoma. Elevated blood dopamine or epinephrine levels aren’t as informative diagnostic signals because they can fluctuate and aren’t as specific to the tumor’s activity. Decreased urinary VMA would be contrary to what typically happens, since VMA is usually increased along with HVA in this condition.

Neuroblastoma often produces catecholamines, which are broken down into metabolites that are excreted in urine. The main urinary metabolites used in this context are homovanillic acid (HVA) and vanillylmandelic acid (VMA). When the tumor is active, dopamine metabolism increases, leading to elevated HVA in the urine. This makes urinary HVA a reliable marker for suspected neuroblastoma.

Elevated blood dopamine or epinephrine levels aren’t as informative diagnostic signals because they can fluctuate and aren’t as specific to the tumor’s activity. Decreased urinary VMA would be contrary to what typically happens, since VMA is usually increased along with HVA in this condition.