Multilevel Pedicular Osteotomies for En Bloc Resection of a Primary Ewing Sarcoma of the Subaxial Cervical Spine with Pedicle Screw Reconstruction

Primary Ewing's Sarcoma affecting the Central Nervous System: A single-center experience and Narrative review

BACKGROUND AND OBJECTIVES

Ewing's sarcoma (EWS) is a malignant round-cell tumor arising from the bone and soft tissue. It is a disease of children and young adults. EWS affecting the central nervous system (cranial and spinal column) is relatively rare with an annual incidence of approximately one case per million in the Western population. Due to their rarity, very few studies are available in the literature. We present our experience of managing 21 such cases, highlighting their clinical, and radiological findings, treatment strategy, and surgical outcomes in patients with primary EWS affecting the central nervous system.

MATERIALS AND METHODS

We retrospectively collected hospital records of patients with primary EWS affecting the CNS (cranial and spinal column), who had been surgically treated in our Neuroscience Center between 2015 and 2023. Patients' demographics, presentation, radiological findings, treatment strategy including surgery and biopsy followed by adjuvant therapy, and outcome at discharge, and the latest follow-up were analyzed from our database.

RESULTS

There were sixteen male and five female patients with a mean age of 18.22 ± 12.73 years (ranging from 6 months to 59 years). The commonest presentation was headache and vomiting in cranial lesions (5/13 patients, 38.46%), and back pain in spinal lesions (4/8 patients, 50%). The site of lesions was cranial in thirteen patients (61.9%) and spinal column in eight patients (38.1%). The commonest site was the frontal region in the cranial group (6 patients, 46.15%) and the lumbar region in the spinal group (4 patients, 50%). All patients underwent surgical intervention [tumor resection (18) and biopsy (3)]. Tumor resection was achieved in 18 patients (85.71%). The extent of resection was gross-total excision in 9 patients (42.86%), near-total excision in 5 patients (23.8%), and tumor decompression in 4 patients (19%). Four patients underwent spinal instrumentation. Fifteen patients (71.42%) received multiagent chemo-radiotherapy according to institute protocol. Five patients (23.8%) with poor KPS expired within 6 months of surgery and could not receive adjuvant therapy. Two patients (9.52%) improved symptomatically, and nine patients (42.86%) remained asymptomatic at a mean follow-up of 25.1 ± 29 months. One patient (4.76%) after receiving 2 cycles of adjuvant therapy had initial improvement but expired later due to disease progression. Four patients after adjuvant chemo-radiotherapy (19%) expired due to systemic spread.

CONCLUSION

Primary EWS affecting the central nervous system is a rare variety. A detailed radiological assessment can aid in adequate planning for safe maximal resection. Timely tissue diagnosis is essential for initiating early treatment. Radical excision followed by adjuvant therapy offers a favorable outcome. Postoperative adjuvant chemo-radiotherapy aids in optimal disease control and surgical outcome. With the current treatment strategy, good surgical outcomes can be achieved. However, metastasis is not uncommon and should be evaluated regularly.

[An application of posterior cervical and transoral approaches to treating primary malignant osseous tumors in craniovertebral junction]

Objective

To investigate the surgical method for primary malignant osseous tumors in the craniovertebral junction (CVJ) and its effectiveness.

Methods

The clinical data of 7 patients with primary malignant osseous spinal tumors in CVJ, which collected between September 2010 and April 2019, were retrospectively analyzed. There were 5 males and 2 females, aged 23 to 75 years (median, 56 years). All patients were diagnosed as chordoma in 4 cases, plasmacytoma in 2 cases, and fibrosarcoma in 1 case. The disease duration ranged from 0.7 to 36.0 months, with an average of 12.2 months. Lesion location: 1 case of C _{0, 1}, 3 cases of C ₂, 1 case of C _{1, 2}, 1 case of C _{2, 3}, and 1 case of C _0-2. Preoperative visual analogue scale (VAS) score was 6.7±2.1, the Japanese Orthopaedic Association (JOA) score was 15.6±2.4. According to American Society of Spinal Cord Injury (ASIA) grading system, there was 1 case of grade C, 1 case of grade D, and 5 cases of grade E. According to Enneking stage of spinal malignant tumor, there was 1 case of stage ⅠB, 2 cases of stage ⅡB, and 4 cases of stage Ⅲ. According to Weinstein-Boriani-Biagini (WBB) stage, there was 1 case of 5-8/A-D, 1 case of 4-9/A-D, 1 case of 6-7/B-D, 1 case of 6-7/A-D, 2 cases of 1-12/A-D, and 1 case of 3-10/A-D. All these patients were treated with tumor extended resection, bone graft fusion, and internal fixation via posterior cervical approach, as well as tumor (stage Ⅰ or stage Ⅱ) boundary resection via transoral or submandibular approach. Meanwhile, anterior reconstructive fusion was procedured with bone grafting Cage needed to place the internal fixation.

Results

The operation time was 307-695 minutes (mean, 489.57 minutes), and the intraoperative blood loss was 400-2 000 mL (mean, 1 107.14 mL). There was no intraoperative injury in vertebral artery and spinal cord or any related postoperative complications, including incision infection, intracranial infection, and pulmonary infection. All the patients were followed up 3-57 months (mean, 21 months). Postoperative X-ray film and CT showed that the internal fixation screw was firm and in a satisfactory position, and the bone graft was fused at 3-6 months after operation. Symptoms such as neck pain, limb numbness, and fatigue relieved to different degrees after operation. At 3 months after operation, the VAS score improved to 1.7±0.8 ( t=7.638, P=0.000); while the JOA score improved to 16.1±1.5, but no significant difference was found when compared with preoperative score ( t=1.549, P=0.172). According to ASIA grading system, 1 patient with grade C had upgraded to grade D after operation, while the remaining patients had no change. There were 4 cases of recurrence after operation, in which those patients were with high malignancy of tumors before the first surgery. Their tumors also affected a wide range of slope or surrounding soft tissues and could not be completely removed. Among the 4 cases, 1 patient underwent transoral tumor removal operation again, while the other 3 cases gave up further treatment. There was no recurrence among the remaining 3 cases.

Conclusion

Primary malignant osseous tumors in the CVJ can be completely exercised via means of trabsoral or submandibular approach. Meanwhile the anterior reconstruction can be achieved by placing special Cage specimen. These two methods together with postoperative adjuvant treatments such as radiotherapy and chemotherapy can improve the survival time of patients and reduce tumor recurrence.