Primary epidural extra-osseous Ewing sarcoma/peripheral primitive neuroectodermal tumor of the cervical spine curatively treated by surgery and adjuvant chemoradiotherapy: A case report and review of the literature

Introduction: Primary epidural extra-osseous Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) is a rare entity included in the Ewing sarcoma family of tumors (ESFTs) that is associated with an unfavorable prognosis. Methods: We described the case of a patient with primary epidural extra-osseous ES/pPNET of the cervical spine, and reviewed the relevant literature for reports on this rare malignant tumor. Our research yielded 24 articles describing 40 patients. We analyzed these reports to identify factors associated with long-term survival. Results: A 30-year-old woman presented with pain and numbness in the right scapula and right upper limb. Cervical MRI showed an epidural mass extending into the right C6-7 foramina. We performed gross total resection of the mass; the histological diagnosis was ES/pPNET. We also performed adjuvant chemoradiotherapy after the operation. No recurrence has been observed for 10 years. Based on the review of the literature, we conducted a Kaplan-Meier analysis of 36 patients who underwent surgery. The analysis showed that the median survival time in patients treated with adjuvant chemotherapy was significantly longer than that in patients treated without adjuvant chemotherapy (25 months vs. 18 months, p = 0.002, log-rank test), whereas neither the mode of resection nor the performance of adjuvant radiotherapy significantly influenced survival. Conclusions: Long-term survival (>10 years) was obtained by gross total resection and adjuvant chemoradiotherapy. Adjuvant chemotherapy was associated with a long median survival time in a patient with epidural extra-osseous ES/pPNET of the cervical spine.