Final answer:
A nontender abdominal mass with elevated VMA and HVA is more likely to be caused by a neuroblastoma, as these urine metabolites are indicative of a tumor in the sympathetic nervous system, often located in the adrenal medulla.
The correct answer is options 4
Step-by-step explanation:
The cause of the nontender abdominal mass associated with elevated vanillylmandelic acid (VMA) and homovanillic acid (HVA) is most likely due to a neuroblastoma. Neuroblastoma, a cancer of the sympathetic nervous system, often presents in the adrenal medulla, and it secretes catecholamines and their metabolites such as VMA and HVA, which are detectable in urine.
Although pheochromocytomas also arise from the adrenal medulla and secrete catecholamines, they are more commonly associated with symptoms related to hypertension rather than with nontender abdominal mass. Renal cell carcinoma is associated with the kidneys and does not typically elevate VMA and HVA levels, while adrenal adenoma usually manifests with hormone imbalances rather than increased VMA and HVA. So, The correct answer is options 4