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.