Primary intradural extramedullary Ewing sarcoma in the lumbar area: A case report.

Primary intradural extramedullary Ewing sarcoma (IEES) is the rarest type of Ewing sarcoma. Extreme caution is required for the diagnosis of IEES because benign intradural spinal tumors can be mistaken for IEES in the early stages of imaging and clinical evaluation. IEES tumors have no standardized treatment guidelines because of the lack of research on the therapeutic aspects of these tumors. Herein, we present a case of primary IEES in a male adolescent with a fast progression of the disease. Diagnosis of IEES was suspected with imaging (computed tomography scan and lumbosacral magnetic resonance imaging) and was confirmed with histology and immunohistochemistry (positive reactivity for CD99 and FLI1). He was successfully treated with surgical intervention with no radiotherapy or chemotherapy. Imaging studies are helpful in making the initial diagnosis of intradural extramedullary Ewing sarcoma. Surgery is considered to be a successful method of treatment for this condition.