Roentgenographic-pathologic correlation of diffuse sclerosis in Ewing sarcoma of bone

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• Ewing sarcoma (ES) is a primary bone cancer.
• Diffuse sclerosis (DS) is a radiographic finding in ES.
• The pathologic basis of DS in ES is not well understood.

Purpose of the Study:

• To describe the roentgenographic and histologic features of diffuse sclerosis in Ewing sarcoma.
• To correlate diffuse sclerosis with bone viability and new bone formation in ES.

Main Methods:

• Review of 210 cases of Ewing sarcoma from the Intergroup Ewing Sarcoma Study.
• Radiographic analysis for diffuse sclerosis (DS).
• Histologic review of biopsies, blinded to radiographic findings, to assess bone viability and new bone formation.

Main Results:

• 37.6% of ES cases showed diffuse sclerosis (DS), often mixed with lysis and periosteal reaction.
• Cases with DS had a significantly higher incidence of dead bone (83%) compared to those without DS (23%).
• 10% of cases with DS exhibited appositional new bone formation on dead bone, unlike cases without DS.

Conclusions:

• Diffuse sclerosis on radiographs of Ewing sarcoma is associated with extensive dead bone.
• DS may represent a reactive process involving new bone formation on necrotic bone in ES.
• Further investigation into the pathogenesis of DS in ES is warranted.