Primary intradural extramedullary extraosseous Ewing’s sarcoma/peripheral primitive neuroectodermal tumor (PIEES/PNET) of the thoracolumbar spine: A case report and literature review

Abstract

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.

Adult Intradural Extramedullary Ewing’s Sarcoma of the Lumbar Spine and Involving the Intervertebral Foramen: A Case Report

“…Chest CT are sensitive for detecting lung and other distant or nodal metastases [1]. However, in previous literatures, masses were mostly seen only in the spinal canal [5,6,10,12,22]. In our case, the mass was not only found in the spinal canal, but also in one side of the intervertebral foramen.…”

“…The symptomatology is similar with other space-occupying lesion of the spinal cord, influenced by mass effect or invasion of adjacent structures, and the chief complaint is pain as in our case [1,5,12,14,22]. Such clinical manifestations are difficult to distinguish from other intraspinal tumors and may even be ignored by patient at early stage [6,10]. Thus, diagnosis of these neoplasms is delayed.…”

“…Reviewing the literature, nearly 50 cases of IEES has been reported from 1997 to 2022 [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. IEES usually affects the lumbar/ sacral region as in our case [12].…”

“…Even if the imaging findings lack specificity, MRI is the preferred choice for tumor assessment in ESFT, including EES [1,10]. MRI reveals iso-signal intensity on T1WI, hypersignal intensity corresponding to necrosis or cystic change on T2WI, and irregular enhanced signaling after gadolinium administration [1,10,14].…”

Magnetic resonance imaging findings of the primitive neuroectodermal tumour in lumbosacral spinal cord in a cat

“…PNETs are rare malignant neuroendocrine tumours composed of small, undifferentiated or neuroectodermal cells (Ma et al., 2020). PNET is a member of the Ewing sarcoma family of tumours (Pu et al., 2021). In humans, the common sites of PNETs are the paraspinal and retroperitoneal areas and extremities (Ottóffy & Komáromy, 2020).…”