Primary Extraskeletal Ewing Sarcoma of the Thoracic Spinal Epidural Space: A Case Report

Cases of extraskeletal Ewing sarcoma (EES) originating primarily within the spinal epidural space, are very rare and have a very poor prognosis. There is no standard therapy for this disease. We report the case of a 23-year-old man presenting with symptoms of back pain and numbness of both legs for 10 days. Imaging studies revealed a dorsal soft-tissue, extradural mass at the T8-9 vertebral level. The patient underwent a laminectomy and complete excision of the tumor. The EES diagnosis was confirmed by histologic analysis including immunohistochemistry and by presence of the EWS-ERG due to the t (21:22) (q22:q12) chromosomal translocation by a reverse transcriptase-polymerase chain reaction (RT-PCR). This is the first report of spinal epidural EES with presence of the EWS-ERG fusion transcript. Post-operatively, the patient received aggressive adjuvant chemotherapy and radiotherapy. At 63 months after surgery, the patient is without clinical or radiological evidence of recurrent or metastatic disease. Early discovery of EES and a complete resection followed by the aggressive treatment with radiation and chemotherapy may improve disease-free and overall survival.