Primary thoracolumbar Ewing's sarcoma presenting as isolated epidural mass

Background context: Ewing's sarcoma is the most common childhood malignancy of bone, but it rarely occurs as a primary extraosseous epidural tumor. Purpose: To heighten awareness and treatment options of this rare (epidural) presentation of Ewing's sarcoma. Study design: Case report. Methods: Retrospective review. Results: We present a 13-year-old boy with progressive low back and bilateral lower extremity pain and normal neurologic examination. Magnetic resonance imaging showed an extradural tumor in the dorsal epidural space from T11 to L1. He underwent a posterior laminoplasty and gross total resection of tumor; histopathological diagnosis was consistent with Ewing's sarcoma. After surgery, the patient underwent adjuvant chemotherapy and irradiation. At 10 months follow-up, the patient is neurologically intact without evidence of residual disease. Conclusions: Ewing's sarcoma of the epidural space should be considered in the differential diagnosis of epidural mass lesions. Because wide surgical margins cannot be obtained, close follow-up with a low threshold for reoperation is mandatory.