Periosteal reaction described as 'sunburst' pattern on plain radiograph is most characteristic of which bone tumor?

• A Ewing sarcoma
• B Chondrosarcoma
• C Giant cell tumour
• D Osteosarcoma ✓

Explanation

Sunburst periosteal reaction — radiating spicules of new bone perpendicular to the cortex — is the classic periosteal pattern of osteosarcoma. It represents tumour stimulating periosteal bone formation along Sharpey's fibres. Ewing sarcoma more characteristically shows an 'onion-skin' (laminated) periosteal reaction, though both patterns can overlap. Chondrosarcoma typically shows lobulated lytic lesion with chondroid matrix calcification (arcs and rings) and less aggressive periosteal reaction. Giant cell tumour lacks periosteal reaction as it arises in the epiphysis without cortical penetration in early stages.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.