Findings:
The X-rays show the characteristic finding of a Codman triangle and periosteal reaction of the distal aspect of the femur. The distal half of the femur contains a heterogeneous lesion resulting in medullary and cortical bone destruction with a moth-eaten appearance.
No obvious fracture is identified. Thus, findings are suggestive of osteosarcoma.

Impression:
Findings concerning high-grade osteosarcoma of the distal right femoral diaphysis.

Recommendations:
For your training purposes, recommendations are not included in this report.