Molecular reclassification of pediatric supratentorial ependymomas reveals distinct clinical and surgical features by location
Background
Supratentorial pediatric ependymomas (ST-EPNs) are rare and biologically diverse central nervous system tumors. The 2021 WHO molecular classification has significantly refined their diagnostic framework, providing crucial insights into prognosis and guiding therapeutic strategies. Understanding the specific clinical, surgical, and molecular characteristics of these tumors, particularly in relation to their location, is vital for optimizing patient management and improving long-term outcomes, addressing a key gap in personalized neuro-oncology.
Study Design
Researchers retrospectively reviewed 12 pediatric patients with histologically confirmed supratentorial ependymomas treated between 2007 and 2023 at a single institution. Tumors were reclassified according to the 2021 WHO molecular criteria. The study evaluated clinical presentation, imaging characteristics, tumor location (intraventricular vs. extraventricular), molecular subtype, extent of resection, adjuvant therapies, recurrence patterns, and long-term outcomes. Surgical management details, including the achievement of Gross Total Resection (GTR), were meticulously assessed.
Results
Molecular profiling identified ZFTA fusion-positivity in 11 of 12 cases and YAP1 fusion-positivity in one case. Gross total resection was achieved in 11 of 12 patients, with one patient undergoing near-total resection due to vascular encasement. Intraventricular tumors presented earlier, necessitated complex surgical management, and were associated with a higher overall treatment burden. Conversely, extraventricular tumors commonly presented with seizures and distinct cystic imaging features, leading to favorable postoperative recovery. Recurrence was observed in 3 patients, all successfully managed with repeat surgery and adjuvant therapy. At a mean follow-up of 8 years, all patients were alive with good neurological outcomes. Secondary neoplasms were noted in isolated cases following multimodal treatment.
All 12 pediatric patients with supratentorial ependymomas were alive with good neurological outcomes at a mean follow-up of 8 years.
Key Findings
- Molecular profiling identified
ZFTAfusion in 11 of 12 pediatric ST-EPNs andYAP1fusion in 1 case. - Intraventricular ST-EPNs presented earlier, required complex surgery, and had higher treatment burden.
- Extraventricular ST-EPNs presented with seizures, cystic features, and favorable postoperative recovery.
- Gross total resection was achieved in 11 of 12 patients, with 3 experiencing recurrence successfully managed.
- All 12 patients were alive with good neurological outcomes at a mean follow-up of 8 years.
Why It Matters
This study underscores the critical importance of integrating molecular classification with anatomical location for pediatric supratentorial ependymomas. The distinct clinical courses and surgical challenges associated with intraventricular versus extraventricular tumors suggest that treatment protocols should be tailored accordingly. Clinicians should consider molecular subtype and tumor location for more precise prognostic assessment and individualized treatment planning, potentially optimizing surgical approaches and adjuvant therapy strategies. While a single-institution retrospective study, these findings provide valuable real-world data that can inform larger prospective studies and refine current neuro-oncology guidelines for these rare and complex tumors.
ependymoma
pediatric cancer
brain tumor
neuro-oncology
molecular classification
zfta fusion