Exploring Maintenance Therapy in Pediatric Embryonal Tumor With Multilayered Rosettes.

Embryonal tumors with multilayered rosettes (ETMR) represent a distinct entity characterized by aggressive behavior. Historical retrospective analyses have documented dire overall survival rates ranging from 0% to 14% at 1 year. However, a contemporary report by Khan and colleagues shows overall survival rates reaching 29% at 2 years and 27% at 4 years. We present the case of an 18-month-old girl diagnosed with ETMR, confirmed by chromosome 19 microRNA cluster amplification following initial presentation with focal seizures. The patient underwent a combination of surgical interventions, high-dose chemotherapy with stem cell rescue, and proton therapy, achieving a disease-free status after completing standard treatment. Subsequently, a 12-month maintenance regimen comprising intrathecal topotecan, oral sodium valproate, and oral cis-retinoic acid was administered. The maintenance therapy was well tolerated, with manageable adverse effects. The patient remains progression-free for 32 months postmaintenance therapy (50 months from initial presentation). This study explores the feasibility and safety profile of maintenance therapy in ETMR. Future studies may explore this approach to determine its efficacy in children with ETMR.