Ewing sarcoma - fibula
Pathologically proven Ewing sarcoma.
Ewing sarcoma is an aggressive bone tumor observed in the first two decades of life. Second most common malignant bone tumor in children, presenting a higher prevalence in boys than in girls (3:1 ratio).
The typical clinical presentation includes:
- Pain and swelling at the site of the tumor. Pain often referred to the adjacent joint.
- Patients may present with nonspecific symptoms such as fever, increased erythrocyte sedimentation rate, and leukocytosis, or with weight loss and anemia.
Mainly located near the metaphysis/diaphysis of long bones. Less often in flat bones or vertebral bodies.
Usually osteolytic lesions (motheaten, or permeative) with a soft-tissue component.
Periosteal reactions are common:
- Spiculation (periosteal new bone formation radiating into the soft tissues)
- Onionskin periosteal ossification.
- Codman triangle: elevated ossified periosteum at the margin of the subperiosteal tumor.
- "Sunburst" appearance
On imaging, the main differential diagnosis is osteosarcoma.