A 12-year-old boy presents with pain and swelling in the mid-shaft of the femur. X-ray shows an onion-peel (lamellated) periosteal reaction with a permeative lytic lesion in the diaphysis. The most likely diagnosis is:

• A Langerhans cell histiocytosis
• B Osteosarcoma
• C Osteomyelitis
• D Ewing sarcoma ✓

Explanation

Ewing sarcoma classically presents in the diaphysis of long bones with a permeative lytic lesion and lamellated onion-skin periosteal reaction. Osteosarcoma typically involves the metaphysis with a mixed lytic-blastic lesion and sunburst or Codman triangle periosteal reaction. Acute osteomyelitis can show periosteal reaction but usually has a more localized clinical presentation. LCH causes well-defined lytic lesions, typically in the skull.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.