SYP and glioblastoma: GBMs with primitive neuronal components (PNC) are a rare subtype, first formally recognized by the World Health Organization (WHO) in 2016.[2] These tumors account for approximately 0.5% of all GBM cases and are often associated with a high propensity for CSF dissemination and ECM.[3] GBM-PNC exhibits both traditional astrocytic regions with high glial fibrillary acidic protein (GFAP) expression and primitive neuronal regions with low GFAP expression and high expression of neuronal markers such as synaptophysin (SYN), soluble protein-100, and neuron-specific enolase.