**Question:** All of the following are small round blue cell tumours except

A. Ewing's Sarcoma
B. Hodgkin's Lymphoma
C. Neuroblastoma
D. Burkitt's Lymphoma

**Core Concept:** Small round blue cell tumours (SRBCTs) are a group of malignant tumors characterized by small, round, blue cells under the microscope. These tumours mainly involve the bone marrow, blood, and lymphatic system.

**Why the Correct Answer is Right:** Hodgkin's Lymphoma is a type of non-small round blue cell tumour, specifically a lymphoma, characterized by the presence of distinct cell types known as Reed-Sternberg cells. Burkitt's Lymphoma is another type of lymphoma, typically affecting children, and is known for its characteristic presentation and epidemiology.

**Why Each Wrong Option is Incorrect:**

A. Ewing's Sarcoma is a type of bone and soft tissue sarcoma, not a lymphoid malignancy like the other options.

B. Neuroblastoma is a malignant tumour of neuroectodermal origin, primarily affecting infants and children, not belonging to the SRBCT category.

**Clinical Pearl:** Understanding SRBCTs and their distinct characteristics, such as cell morphology and epidemiology, is crucial for distinguishing between different types of lymphoid malignancies and solid tumours. This knowledge helps in accurate diagnosis, treatment planning, and patient management.