**Question:** Germ cell tumor(s) of paediatric includes all except

A. Germ cell tumor (GCT) is a group of malignancies originating from germ cells. Germ cells are the cells that develop into gametes (sperm in males and eggs in females). In adults, GCTs are mostly found in the testes (male) and ovaries (female), while in paediatric population, they can occur in various locations.

**Correct Answer:** Germ cell tumors can occur in various locations in the pediatric population, including:

1. **Anterior mediastinum (e.g., thymus gland)**: Thymus-derived GCTs include thymoma and thymic carcinoma, while extrathymic GCTs include seminoma, non-seminoma, teratoma, yolk sac tumor, and mixed germ cell tumors.
2. **Pelvis (e.g., testes and ovaries)**: In males, GCTs are mostly testicular, while in females, they are mostly ovarian. However, in the pediatric population, GCTs can occur in the undescended testes, which are the testes that do not descend into the scrotum during fetal development.
3. **Retroperitoneum (e.g., epididymis, spermatic cord)**: GCTs can arise from germ cells within the epididymis, spermatic cord, or retroperitoneum. In the pediatric population, GCTs may present as a palpable mass in the scrotum or inguinal canal.
4. **Central nervous system (CNS)**: GCTs can arise from germ cells in the CNS, including pineal gland, pituitary gland, and other brain regions.
5. **Abdominal wall (e.g., inguinal canal)**: GCTs can occur in the inguinal canal as a result of undescended testes or other structures.
6. **Liver** (e.g., hepatoblastoma): GCTs can arise from germ cells in the liver, such as hepatoblastoma, which is a common pediatric liver tumor.

Given the wide range of germ cell tumors in the pediatric population, the correct answer is:

**Correct Answer: Germ cell tumors in the pediatric population can occur in various locations, including but not limited to, anterior mediastinum, retroperitoneum, CNS, abdominal wall, and liver.**

These tumors can present with various clinical features, such as abdominal mass, hydrocele, hydroorchid, or hydrocele and orchid. Differentiating between primary and secondary tumors is crucial, as the treatment and prognosis depend on the primary site of origin.

Core Concept: Germ cell tumors are a group of tumors that arise from germ cells. These cells are the precursors of gametes, which are reproductive cells (sperm in males and eggs in females). In paediatric patients, the majority of GCTs arise from germ cells in the testes, ovaries, or other locations like the liver, lungs, and mediastinum.

Why the correct answer is "Germ cell tumors in