Clinical, surgical, and molecular features of pediatric supratentorial ependymomas: a single-institution experience

Supratentorial pediatric ependymomas (ST-EPNs) represent a rare and biologically heterogeneous subgroup of central nervous system tumors. The 2021 WHO molecular classification has redefined their diagnostic framework, emphasizing prognostic and therapeutic implications. This study analyzes clinical, surgical, and molecular features of pediatric ST-EPNs treated at a single-institution, with particular focus on outcomes and prognostic variables.

We retrospectively reviewed pediatric patients with histologically confirmed supratentorial ependymomas treated between 2007 and 2023. Tumors were reclassified according to the 2021 WHO molecular criteria. Clinical presentation, imaging characteristics, tumor location, molecular subtype, extent of resection, adjuvant therapies, recurrence patterns, and long-term outcomes were evaluated.

Twelve patients were included (mean age 7.4 years). Two tumors were intraventricular and ten extraventricular. Molecular profiling identified ZFTA fusion-positivity in 11 cases and YAP1 fusion-positivity in one case. Gross total resection was achieved in 11 of 12 patients, whereas one patient underwent near-total resection because of vascular encasement of the middle cerebral artery, making complete resection unsafe. Intraventricular tumors presented earlier, required complex surgical management, and were associated with higher treatment burden. Extraventricular tumors commonly presented with seizures and cystic imaging features, with favorable postoperative recovery. Recurrence occurred in 3 patients, 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 observed in isolated cases following multimodal treatment.

This single-institution molecularly reclassified series highlights clinically relevant differences between intraventricular and extraventricular pediatric supratentorial ependymomas in presentation, surgical complexity, and treatment burden. Our findings support maximal safe resection as the central therapeutic strategy while emphasizing the value of integrated molecular diagnostics and prolonged surveillance, particularly in light of late recurrence and secondary neoplastic events.