Which laboratory finding would remain normal in a seminoma?

In the case of a seminoma, which is a type of testicular germ cell tumor, one of the key laboratory findings is that alpha-fetoprotein (AFP) levels remain normal. This is significant because while seminomas can be associated with elevated levels of human chorionic gonadotropin (HCG) and lactate dehydrogenase (LDH) in some cases, AFP is typically not produced by seminomas.

Seminomas are classified as pure germ cell tumors, and their markers differ from those seen in non-seminomatous germ cell tumors, which often secrete AFP as part of their tumor marker profile. Therefore, the normalcy of AFP is a distinguishing factor that can help clinicians differentiate between seminomas and other testicular tumors that may produce this marker, such as yolk sac tumors.

Prostate-specific antigen (PSA) is not relevant in this context, as it is specifically related to prostate conditions and does not play a role in testicular tumors. Thus, while HCG and LDH might be elevated in some patients with seminomas, AFP would consistently remain at normal levels, making it the correct answer.