Akademik Veri Yönetim Sistemi
Turkish neurosurgery, 2025 (SCI-Expanded, Scopus, TRDizin)
Aim: DNA methylation-based tumor classification (MBTC) has emerged as a valuable adjunct for diagnostically challenging central nervous system (CNS) tumors. MBTC is routinely applied at Acibadem University to pediatric cases with indeterminate morphology or inter-center dis-agreement. This work presents a single-center experience and highlights the urgent need for multi-institutional collaboration in Türkiye and surrounding regions lacking access to methylation platforms, with the aim of enhancing diagnostic precision and neuropathological practice.
Material and methods: All pediatric patients who underwent MBTC between November 2023 and July 2025 were retrospectively identified. Clinical, histological, and molecular data were extracted and corre-lated with methylation results. Concordance between histopathology and MBTC was catego-rized as concordant, minor discordance, major discordance, novel classification, or unclassifiable.
Results: A total of 48 tumors were profiled (26 females [54%]; 22 males [46%]; median age, 6.5 years; range, 0-17). The most frequent localization was supratentorial (n = 18, 36%). Of the entire cohort, concordance was 58%. Excluding unclassifiable cases, concordance among evaluable tumors was 67%. Discordance occurred in 11 cases (23%), including 6 (13%) with major discrepancies. Concordance was significantly associated with tumor localization (p = 0.028) but not WHO grade (p = 0.17) and classifier confidence (p = 0.73).
Conclusion: MBTC is a valuable complementary tool in the diagnostic workup of pediatric CNS tumors, particularly in morphologically ambiguous and ultra-rare cases. It should be integrated with conventional histopathology rather than viewed as a replacement, as it may prevent prognostic misclassification and inappropriate treatment in selected patients.