Central Nervous System Embryonal Tumour With PLAGL Amplification Lacking Typical Embryonal Morphology: Diagnostic Pitfall in a Paediatric Case

Summary Central nervous system embryonal tumour with PLAGL amplification (ET‐PLAGL) is a methylation‐defined tumour characterised by PLAGL1 or PLAGL2 amplification. ET‐PLAGL may not be readily recognised on histological assessment and requires molecular profiling for accurate classification. PLAGL1 protein expression detected by immunohistochemistry and PLAGL1 gene amplification confirmed by fluorescence in situ hybridisation may serve as adjunctive findings in the diagnosis of ET‐PLAGL. This case highlights discordance between histological appearance and molecular classification, representing a potential diagnostic pitfall.