SPECC1L NTRK2 fusion harboring adult onset high grade glioma and its diagnostic implications

High-grade gliomas (HGGs) are aggressive brain tumors with poor outcomes and limited treatment options. Molecular profiling has refined glioma classification and revealed rare but actionable alterations such as NTRK fusions. This case report aims to describe the molecular characterization of an adult high-grade glioma harboring NTRK2 fusion and highlight its diagnostic relevance. Comprehensive molecular profiling was performed using next-generation sequencing (NGS) with custom QIAseq DNA and RNA panels targeting 118 cancer-related genes and 12 Central nervous system (CNS) fusion genes, respectively. DNA methylation-based classification was conducted to establish the molecular class and refine tumor diagnosis. Methylation profiling identified a tumor as Mc Adult-Type Diffuse High-Grade Glioma, IDH-wildtype, Subtype B (novel), CNS WHO grade 4. RNA sequencing revealed a novel SPECC1L::NTRK2 fusion, while DNA sequencing detected mutations in MAPK, PI3K-AKT, and PLCγ pathways. The patient had a prolonged survival of 42 months post-surgery. This case emphasizes the diagnostic and clinical significance of comprehensive molecular profiling in identifying rare, targetable fusions such as NTRK2 in unclassified CNS tumors and supports incorporating comprehensive molecular profiling into routine diagnostics for precision oncology.