Primary intradural extraosseous Ewing sarcoma of the spine: case report and literature review.

BACKGROUND AND IMPORTANCE: To report a rare case of spinal intradural extraosseous Ewing sarcoma in an adult and review current literature. Although Ewing sarcoma belongs to the family, the treatment modalities are different, and thus the correct diagnosis is very important despite its rare occurrence. CLINICAL
PRESENTATION: A 56-year-old woman presented with nocturnal bilateral buttock and leg pain. Magnetic resonance imaging (MRI) showed an enhancing intradural extramedullary extraosseous tumor at L1. INTERVENTION: A T12-L2 laminectomy was performed to resect the tumor. Immunohistochemical analysis confirmed the diagnosis of Ewing sarcoma. A thorough diagnostic workup did not reveal any bony origin of the tumor. Primary intradural central nervous system Ewing sarcoma is infrequently encountered and shares imaging and histopathological features with central primitive neuroectodermal tumors. Establishment of the right diagnosis is crucial because it mandates a distinct workup and treatment modality different from that for central primitive neuroectodermal tumor. Although osseous Ewing sarcoma predominantly occurs in children and young adults, extraosseous central nervous system Ewing sarcoma is not uncommon in adults and should therefore be considered in the differential diagnosis of extraosseous small blue cell tumors in adult patients.