Pediatric Embryonal Tumor With Multilayered Rosettes (ETMR): Retrospective Single-Center Case Series of 4 Patients

Background: Embryonal tumor with multilayered rosettes (ETMR) is a rare, aggressive pediatric tumor whose diagnosis now relies on integrated molecular criteria. Observations: Between 2015 and 2025, we treated 4 children (18 mo to 5 y). The first diagnosis was based on morphology and LIN28A immunoreactivity, the second on C19MC amplification, and the last 2 on methylation profiling after weak or absent LIN28A. All received multimodal therapy. One died 18 months after diagnosis; 3 were alive, one beyond 10 years. Conclusions: The series documents clinicopathological heterogeneity in ETMR. Molecular profiling contributed to diagnosis in cases with weak or absent LIN28A immunoreactivity.