Report from the National Pediatric Cancer Foundation - infantile glioma and other non-embryonal central nervous system tumors: evolving molecular advances and current treatment landscape.

Background: Brain tumors in infants represent a rare but clinically challenging subset of pediatric central nervous system (CNS) neoplasms. These tumors are biologically and clinically distinct from those in older children and adults, with a predilection for supratentorial locations, frequent presentation with macrocephaly and signs of increased intracranial pressure, and unique molecular profiles. There have been many advances in molecular profiling, now influencing treatment choice and outcomes. Non-embryonal tumor types-including glial tumors, choroid plexus tumors, craniopharyngioma, ependymoma, teratoma, and germ cell tumors-collectively constitute the majority of infant brain tumors and warrant focused attention. Methods and scope: This review synthesizes the current literature on the epidemiology, molecular biology, clinical presentation, management, and outcomes of non-embryonal brain tumors diagnosed in infants (age ≤12-36 months). Tumor types addressed include low-grade and high-grade gliomas (including the recently defined infant-type hemispheric glioma [IHG]), choroid plexus papilloma and carcinoma, ependymoma, craniopharyngioma, teratoma, and intracranial germ cell tumors. Key findings: Glial tumors are among the most common infant brain tumors, with low-grade gliomas demonstrating excellent survival approaching 100%, while high-grade gliomas carry a significantly worse prognosis. IHGs are a molecularly distinct entity driven by receptor tyrosine kinase (RTK) fusions involving ALK, NTRK1/2/3, ROS1, and MET, with three-year overall survival of approximately 80% and emerging evidence supporting targeted tyrosine kinase inhibitor therapy. Choroid plexus papillomas peak during infancy and are curable with gross total resection, whereas choroid plexus carcinomas have five-year survival rates of 61-65% and require multimodal therapy. Posterior fossa A (PFA) ependymomas predominate in infants and behave more aggressively than other ependymoma subtypes. Craniopharyngiomas, though rare in infancy, present unique surgical challenges given their proximity to the hypothalamic-pituitary axis. Intracranial teratomas are the most common congenital brain tumors. Conclusions: Non-embryonal infant brain tumors encompass a heterogeneous group of neoplasms with widely variable outcomes. Advances in molecular classification-particularly the identification of targetable RTK fusions in IHG-are reshaping therapeutic paradigms. Integrated histopathologic and molecular characterization per the WHO CNS5 classification is essential for accurate diagnosis and optimal treatment planning in this vulnerable population. Collaborative, prospective studies are needed to establish standardized treatment approaches and improve long-term neurocognitive outcomes.