Intradural Extramedullary Nonconus Nonfilum Spinal Ependymomas: Report of a Rare Variant and Newer Insights into Their Histogenesis with Proposal of a Classification Scheme and a Management Algorithm Based on a Review of Literature

A comprehensive evaluation of imaging features in pediatric spinal gliomas and their value in predicting tumor grade and histology

PURPOSE

Pediatric spinal cord gliomas (PSGs) are rare in children and few reports detail their imaging features. We tested the association of tumoral grade with imaging features and proposed a novel approach to categorize post-contrast enhancement patterns in PSGs.

METHODS

This single-center, retrospective study included patients <21 years of age with preoperative spinal MRI and confirmed pathological diagnosis of PSG from 2000-2022. Tumors were classified using the 5th edition of the WHO CNS Tumors Classification. Two radiologists reviewed multiple imaging features, and classified enhancement patterns using a novel approach. Fisher's exact test determined associations between imaging and histological features.

RESULTS

Forty-one PSGs were reviewed. Thirty-four were intramedullary, and seven were extramedullary. Pilocytic astrocytoma was the most common tumor (39.02%). Pain and weakness were the most prevalent symptoms. Seven patients (17.07%) died. Cyst, syringomyelia, and leptomeningeal enhancement were associated with tumor grade. Widening of the spinal canal was observed only in low-grade astrocytomas. There was a significant association between tumor grade and contrast enhancement pattern. Specifically, low-grade PSGs were more likely to exhibit type 1A enhancement (mass-like, with well-defined enhancing margins) and less likely to exhibit type 1B enhancement (mass-like, with ill-defined enhancing margins).

CONCLUSION

PSGs display overlapping imaging features, making grade differentiation challenging based solely on imaging. The correlation between tumor grade and contrast enhancement patterns suggests a potential diagnostic avenue, requiring further validation with larger, multicenter studies. Furthermore, Low-grade PSGs display cysts and syringomyelia more frequently, and leptomeningeal enhancement is less common.

A Case of Spinal Ependymoma Developed in the Extramedullary Location: A Case Report and Literature Review

Intradural extramedullary (IDEM) ependymoma except for tumors originated from the filum terminale or conus medullaris is rare. The present study showed a case of IDEM ependymoma. A 16-year-old boy was referred to our hospital with a complaint of right hypochondriac pain and motor weakness in his right leg. MRI revealed a solitary intradural tumor at Th5–8 level with syringomyelia at Th2–4 level. Microscopic total tumor resection was performed with right hemi-laminectomy of Th4–9. Histological diagnosis was ependymoma (WHO grade 2). Although his leg weakness was worsened transiently, he showed improvement in leg weakness being able to go up and down the stairs 1 month after the surgery. There was no tumor recurrence until now, 7 years after the surgery, without any adjunctive therapies. A total of 44 cases of IDEM ependymoma had been reported in the past literatures. They are thought to arise from ependymal cells which remained during the process of neural tube closure. Like intramedullary ependymomas, most of the IDEM ependymomas have clear border to surrounding tissue and often removed completely. However, a small number of recurrences and malignant transformations had been reported after complete resections despite benign histological features tumors. In the case of totally resected low grade IDEM ependymoma, it is thought to be reasonable to perform long-term periodical radiographic follow-up without postoperative adjunctive therapy.

Ependymoma of the spinal cord with multiple intradural extramedullary ependymomas: The first case report and literature review

Ependymomas are the most prevalent intramedullary neoplasms in adults. Few cases have been reported on exophytic intramedullary ependymoma or multiple non-conus, and non-filum intradural extramedullary (IDEM) ependymomas. Here, we reported a 30-years old female with exophytic ependymoma in T10-11 and multiple IDEM ependymomas in T3-S2 and who's condition ultimately improved. This is the first case of exophytic ependymoma of the spinal cord with multiple IDEM ependymomas.

Extensive craniospinal disseminated metastasis after the resection of intradural extramedullary ependymoma in the craniocervical junction: a case report and literature review

PURPOSE/AIM

Intradural extramedullary (IDEM) ependymomas are very rare, and IDEM ependymomas with craniospinal disseminated metastasis are exceptionally rare; only 2 preoperative cases have been confirmed, and postoperative cases have not been reported.

CASE REPORT

We present a case of a 21-year-old female with an IDEM ependymoma of the craniocervical junction who experienced head and neck pain for more than 1 month. Magnetic resonance imaging (MRI) of the cervical spine revealed a large IDEM cystic lesion located in the medulla oblongata and the upper cervical spinal cord. The patient underwent surgery without complications, and the tumor was completely removed. Histopathological examination revealed a diagnosis of aplastic ependymoma, World Health Organization (WHO) grade III. The patient failed to follow-up with radiotherapy for one month after discharge. Nearly three months after surgery, craniospinal disseminated metastasis was found in the patient; subsequently, chemoradiotherapy was administered to prolong the survival time of the patient. Unfortunately, the patient underwent radiotherapy and chemotherapy for only 7 days; then, the patient gave up treatment and died 5 months later.

CONCLUSIONS

To the best of our knowledge, no other cases of craniocervical junction anaplastic ependymomas with craniospinal disseminated metastasis have been reported in the literature. Total resection does not completely prevent recurrence and metastasis, and MRI of the entire neuraxis and timely postoperative craniospinal radiotherapy are necessary for the treatment of this disease.