A 14-year-old with Ewing's sarcoma of the fibula diaphysis has completed neo-adjuvant chemotherapy with an excellent response. Limb salvage surgery with wide excision is planned. The minimum oncologically safe surgical margin required is:

• A 1 mm (marginal margin)
• B 5 mm of reactive zone
• C 1 cm or more of normal uninvolved tissue (wide margin) ✓
• D Radical resection removing the entire compartment

Explanation

Enneking surgical margins: intralesional (through tumor), marginal (through reactive zone), wide (1 cm of normal tissue beyond the reactive zone), and radical (entire compartment). For malignant bone tumors like Ewing sarcoma, a wide surgical margin of at least 1 cm of normal tissue is the minimum acceptable oncological standard during limb salvage; this margin minimizes local recurrence. A marginal margin passes through the reactive zone and risks leaving microscopic tumor. Radical resection (entire compartment) achieves the best margin but is more morbid and often unnecessary with good chemotherapy response.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.