Pediatric cancer

1. Where is the most common location of pediatric brain tumors?
2. What is Wilm's tumor?
3. What are the two most common types of malignant bone tumors and where are they commonly found?

Answers:
1. Posterior fossa.
2. Wilm's tumor or nephroblastoma develops in the renal parenchyma in children 2-5 years, and may be associated with congenital anomalies.
3. Osteosarcoma most common, followed by Ewing's sarcoma. Osteosarcoma is in the metaphysis of long bones, most commonly in the distal femur. Ewing's arises in long and flat bones, including pelvis, typically in diaphysis.