A 16-year-old boy has a painful lytic lesion of the proximal tibial metaphysis on X-ray with aggressive periosteal reaction showing multiple parallel layers. This 'onion-skin' periosteal reaction is most characteristic of:
- A Osteosarcoma
- B Ewing sarcoma ✓
- C Aneurysmal bone cyst
- D Giant cell tumor
Correct answer: B. Ewing sarcoma
Explanation
Onion-skin periosteal reaction (laminated periostitis) results from repeated episodes of periosteal elevation and new bone formation and is the classic periosteal pattern of Ewing sarcoma. Osteosarcoma more typically shows a Codman's triangle and sunburst/spiculated periosteal pattern along with osteoid matrix. Aneurysmal bone cysts are eccentric expansile lytic lesions without aggressive periosteal reaction. Giant cell tumors are epiphyseal/subarticular lytic lesions without periosteal reaction.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.