Intraspinal Ewing's sarcoma/primitive neuroectodermal tumors.

Intraspinal Ewing's sarcoma (ES) and primitive neuroectodermal tumors (PNET) are very rare, and the characteristics and prognoses of the disease remain unclear. We present an illustrative patient with an intradural, extramedullary PNET arising within the cervical spinal canal, with clinical and radiological manifestations of leptomeningeal spread, and review the reports of a further 77 patients with intraspinal ES/PNET. Cox regression analyses showed that tumor location (extradural, intradural) (p=0.002, RR=4.217, 95% confidence interval [CI] 1.668-10.664) and spinal segment location (cervical, thoracic, lumbar, or sacral) (p=0.017, RR=2.040, 95% CI 1.133-3.673) were independent factors in the prognosis of intraspinal ES/PNET. We concluded that a peripheral PNET may originate within the spinal canal and exhibit leptomeningeal spread similar to that seen in central PNET, and that a patient with an intradural ES/PNET high in the spinal canal is more likely to have a poor prognosis.