**Core Concept**
Germ cell tumors are a type of cancer that arises from the cells responsible for the development of the reproductive system. They can occur in the gonads (testes and ovaries) and extragonadal sites (mediastinum, retroperitoneum, and pineal gland). Germ cell tumors are classified into two main types: seminomatous and non-seminomatous.

**Why the Correct Answer is Right**
Germ cell tumors are a specific category of tumors that originate from primordial germ cells. The correct answer will be a tumor type that does not arise from germ cells. Seminoma and non-seminoma are the two main types of germ cell tumors that occur in the testes and ovaries. Other tumor types, such as lymphoma, carcinoid tumors, and sex cord-stromal tumors, do not originate from germ cells.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because seminoma is a type of germ cell tumor that arises from the germ cells in the testes.
**Option B:** This option is incorrect because non-seminoma is also a type of germ cell tumor that originates from the germ cells in the testes.
**Option C:** This option is incorrect because yolk sac tumor is a type of germ cell tumor that arises from the germ cells in the testes.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that germ cell tumors can arise in both gonadal and extragonadal sites, and they can be classified into seminomatous and non-seminomatous types based on their histological characteristics.

**Correct Answer: D.**