Okay, let's tackle this question. The user is asking about seminomas and wants to know which statement is not false, meaning which one is true. First, I need to recall what seminomas are. They're a type of germ cell tumor, usually found in the testes. Now, the question is looking for the exception—the one statement that is true about seminomas.

The core concept here is the characteristics of seminomas. I remember that seminomas are radiosensitive, which makes them respond well to radiation therapy. They're also more common in younger men, typically between 15-35 years. Another key point is that they often present as painless testicular masses. Histologically, they show uniform cells with clear cytoplasm and a lymphocytic infiltrate.

Now, the correct answer would be the one that correctly states a true fact about seminomas. Let's say the options include something like being radiosensitive, which is true. The other options might be about things like being more common in older men (which is false, as they're more common in younger), or not responding to radiation (which is false because they do respond well).

I need to make sure each incorrect option is addressed. For example, if an option says they're usually bilateral, that's incorrect because seminomas are typically unilateral. Another wrong option might mention a specific marker like AFP being elevated, but seminomas usually don't produce AFP; that's more for non-seminomatous tumors like yolk sac tumors.

The clinical pearl here is that seminomas are sensitive to radiation, so they have a good prognosis when detected early. Also, they're associated with elevated hCG or lactate dehydrogenase, but not AFP. So the key is to remember the markers and treatment response.

**Core Concept**
Seminomas are a radiosensitive, histologically uniform germ cell tumors of the testis, typically occurring in young to middle-aged males. They are characterized by lymphocytic infiltration and a distinct response to radiation therapy compared to non-seminomatous germ cell tumors.

**Why the Correct Answer is Right**
Seminomas are radiosensitive due to their low proliferation rate and high sensitivity to ionizing radiation. They often present as painless testicular masses and are associated with elevated human chorionic gonadotropin (hCG) or lactate dehydrogenase (LDH), but not alpha-fetoprotein (AFP). This radiosensitivity is a key clinical distinction, guiding treatment with radiotherapy for early-stage disease.

**Why Each Wrong Option is Incorrect**
**Option A:** _"Seminomas are more common in older men."_
False: Seminomas peak in incidence between 15–35 years; older men are more likely to have non-seminomatous tumors.
**Option B:** _"Seminomas produce alpha-fetoprotein (AFP)."**
False: AFP elevation is a hallmark of non-seminomatous germ cell tumors (e.g., yolk sac tumors), not seminomas.
**Option C:** _"Seminomas are bilateral in 50% of cases."_
False: Bilateral involvement occurs in <1% of seminomas, unlike some non-seminomatous tumors. **Clinical Pearl / High-Yield Fact** Seminomas are

✓ Correct Answer: B. Schiller-Duval bodies are commonly seen