Retrospective study of incidence and predictors of hemorrhage in pediatric low-grade glioma

Pediatric low-grade gliomas (pLGGs) typically have excellent long-term outcomes. Intratumoral hemorrhage is a rare, potentially dangerous complication. A retrospective study at NYU Langone Health and NYU Grossman School of Medicine (New York, NY) investigated the incidence, timing, and risk factor for hemorrhage in a large contemporary pLGG cohort. The study included 236 pLGG patients treated between 2011 and 2025. Twelve patients (5.1%) experience hemorrhage over 2,234 person-years, for an incidence of 0.54/100 person-years. Hemorrhage typically occurred years after initial tumor diagnosis (median 6.4 years). The presence of a KIAA1549::BRAF fusion in the tumor had the strongest association with hemorrhage, persisting across multivariable models (approximately sixfold increased risk), althoug estimates were limited by low event number. MAPK inhibitor exposure, specifically binimetinib and tovorafenib, was associated with hemorrhage in univariate analysis but partially confounded by fusion status. CSF diversion independently increased risk at brainstem, optic pathway, and hypothalamic locations. The authors conclude that hemorrhage in pLGG is an infrequent late complication associated with tumor biology. Study findings support biology-informed surveillance and personalized management strategies for at-risk children.