Disseminated pediatric low-grade glioma and hydrocephalus: a multinational consortium analysis of incidence and mortality

OBJECTIVE Disseminated pediatric low-grade gliomas (DPLGGs) are a rare subtype of an otherwise common tumor, characterized by leptomeningeal dissemination, with microtumors spreading throughout the CNS. The impact of this dissemination on CSF dynamics remains unexplored. The authors describe the occurrence, treatment, and impact of hydrocephalus on functional outcomes and survival in patients with DPLGG. METHODS This study was a post hoc analysis of a multicenter international cohort study that identified 261 children diagnosed with DPLGG from 30 sites across 13 countries from 1988 to 2025. Demographic, histopathological, radiographic, dissemination pattern, hydrocephalus treatment, and functional outcome variables were collected. The primary outcomes were survival, CSF diversion failure, and time to failure (TTF). Group comparisons were conducted using independent-sample t-tests and chi-square tests. Multivariate logistic regression was performed examining predictors of hydrocephalus in DPLGG. Kaplan-Meier analysis was used to assess survival and TTF. RESULTS One hundred forty-five (55.6%) patients developed hydrocephalus and required CSF diversion. Histopathological diagnosis differed between the groups (p = 0.02). Patients with diffuse leptomeningeal glioneuronal tumor had a 41% (OR 1.408, 95% CI 0.413–4.809) increase in odds of developing hydrocephalus relative to other histopathologies. Tumor dissemination pattern did not significantly impact hydrocephalus development (p = 0.381). There was, however, a significant association between the timing of hydrocephalus diagnosis and CSF diversion and dissemination pattern (p < 0.001). For initial CSF diversion, 124 patients (87.9%) received ventriculoperitoneal shunting (VPS) while the remaining patients underwent either endoscopic third ventriculostomy (ETV) (9.2%) or septostomy (2.9%). Fifty-nine (43.1%) patients who underwent CSF diversion required hydrocephalus reintervention at an overall median TTF of 4.96 months (IQR 0.8–22.4) months. TTF by CSF diversion modality showed no significant difference by Kaplan-Meier analysis (log-rank test, p = 0.90). There was no difference in overall survival (log-rank test, p = 0.95) between the hydrocephalus and nonhydrocephalus groups. However, hydrocephalus was associated with academic difficulties (p = 0.02) and concurrent endocrine disorders (p = 0.03). CONCLUSIONS This study represents the largest and most comprehensive cohort of patients with DPLGG to date. While histopathology and tumor location were associated with hydrocephalus in this cohort, the dissemination pattern was not directly associated with hydrocephalus incidence but rather the timing of hydrocephalus diagnosis. Hydrocephalus does not impact survival in patients with DPLGG; however, it is associated with worse functional outcomes.