Musculoskeletal CT Appearances

Ewing Sarcoma CT Findings

• Destruction of the bone (“moth eaten” pattern)
• Lytic lesions with poor margination
• Most common in the pelvis, long bones, and ribs
• Isodense
• Usually does not calcify
• Medullary canal is usually involved
• Periosteal new bone formation
• Soft tissue mass that usually does not calcify

Other Information About Ewing Sarcoma

Etiology:

• Unknown

Epidemiology:

• Typically presents in childhood or adolescence
• More common in males
• More common in patients with European ancestry

Presentation:

• Palpable mass
• Fracture
• Bone pain that may be nocturnal
• Swelling or tenderness
• Fever
• Fatigue
• Weight loss

Prognosis:

• The 5-year relative survival rates are:
  • Localized: 81%
  • Regional: 77%
  • Distant: 41%
  • All SEER stages combined: 65%

Related Pearls: Bone Tumors