Primary spinal extradural Ewing′s sarcoma (primitive neuroectodermal tumor): Report of a case and meta-analysis of the reported cases in the literature

Abstract

Background:Primary spinal primitive neuroectodermal tumors (PNET) and/or spinal extraskeletal Ewing's sarcoma family tumors (ESET) are rare lesions appearing in the spinal extradural space. One hundred forty-one primary spinal PNETs, including 29 intramedullary lesions, have been reported in the literature. Encountering a case of primary epidural EES/peripheral PNET (pPNET) in sacral level, which is the fifth one occurring at this level in the literature, we have tried to conduct a meta-analysis of the reported cases.Case Description:A 44-year-old lady with epidural EES/pPNET is reported here. She was once operated for L5/S1 herniated disc, which did not ameliorate her symptoms. The clinical, imaging, surgical, and histopathologic characteristics of our case are presented and wide search of the literature is also done. All the reports were level 3 or less evidences and most of the series had missing parts. 106 cases of primary intraspinal (extradural/extramedullary-intradural) EES/pPNET and 29 cases of primary intramedullary PNET (CNS-PNET) have been reported in the literature. The most common clinical presentation in both entities was muscle weakness proportionate to the tumor location. Distant metastasis occurred in 38 of 99 (38%) cases of primary intraspinal EES/pPNET, while the rate of metastasis was 48% in patients with PNETs occurring in the intramedullary region (P > 0.05). One-year survival rate of the patients who underwent chemo-radiation after total or subtotal resection was better than those who did not receive chemotherapy or radiotherapy, or did not have total or subtotal resection. However, this difference was not repeated in 2-year survival rate in any of the tumor groups.Conclusion:It seems that total or subtotal removal of the tumor and adjuvant chemo- and radiation therapy can improve the outcome in these patients.

Adult Primary Spinal Epidural Extraosseous Ewing’s Sarcoma: A Case Report and Review of the Literature

“…The review of the literature on combined pediatric and adult spinal EES/pPNET showed that the lumbar region is the most common site, followed by the thoracic and cervical spine, with the sacral region being the least common (5% of cases) [7, 12]. However, in our analysis of the 46 adult epidural EES/pPNET cases (including our case), we found that the most common site was the thoracic spine (17 cases), followed by lumbar (13 cases), cervical (13 cases), and sacral segments (3 cases).…”

“…The mean diagnostic delay calculated from the previous cases is 4.5 months [7], which is explained by nonspecific symptoms at disease onset. The symptoms commonly include back and/or radicular pain in all patients, paresis in about 70%, sensory disturbances in 35%, and to lesser extent bladder and bowel dysfunction in about 12% of patients [7, 15].…”

“…The symptoms commonly include back and/or radicular pain in all patients, paresis in about 70%, sensory disturbances in 35%, and to lesser extent bladder and bowel dysfunction in about 12% of patients [7, 15]. One case presented with infection superimposed upon spinal epidural EES [16].…”

“…ES and pPNET are small round blue cell tumors; they were originally described as different entities; however, they are now recognized to represent ends of the morphologic spectrum of the ESFTs due to their close molecular relationship [3–7]. Some authors even assume pPNET and ES to be the same tumor with variable neural differentiation, a view that has been recently supported by immunohistochemical and cytogenetic findings [3].…”

“…Some authors even assume pPNET and ES to be the same tumor with variable neural differentiation, a view that has been recently supported by immunohistochemical and cytogenetic findings [3]. The ESFT now includes osseous Ewing's sarcoma, EES, pPNET and Askin's tumor [7–9]. …”