Primary Intradural Extramedullary Extraosseous Ewing's Sarcoma/peripheral Primitive Neuroectodermal Tumor (PIEES/PNET) of the Thoracolumbar Spine: A Case Report and Literature Review

We present a rare case of a primary intradural extramedullary Ewing's sarcoma/peripheral primitive neuroectodermal tumor (PIEES/PNET) in the thoracolumbar spine and review the current literature. We describe the imaging manifestations, pathological features, surgical methods, and patient survival to shed light on the clinical management of this rare tumor. A 32-year-old man experienced progressive low back pain for more than 1 month. An intradural extramedullary tumor from T12 to L2 was detected on magnetic resonance imaging. He underwent a thoracolumbar laminotomy for decompression, complete excision of the intradural extramedullary tumor, and internal fixation with pedicle screws. A histopathological examination confirmed that the tumor was a PIEES/PNET via an immunohistochemical study of the surgically resected tissues. Postoperatively, the patient received chemotherapy and radiotherapy. No recurrence, metastasis, or failure of internal fixation were noted at a 17-month post-surgery radiographic examination. PIEES/PNET of the thoracolumbar spine is extremely rare. Treatment is difficult because the current literature is sparse and cases are rare. Complete resection combined with chemotherapy and radiotherapy effectively reduces recurrence and metastasis.