Targeted next-generation sequencing demonstrated amplification of multiple genes located at 12q12-q15, including MDM2, CDK4, DDIT3, and CLL1, supporting diagnostic revision to a borderline/low-grade malignant mesenchymal neoplasm.<h4>Conclusion</h4>This case highlights that skull-based lesions initially diagnosed as ABC may recur with significant dural destruction and intradural extension, and may demonstrate aggressive neoplastic evolution. This evidence concerns the gene CDK4 and mesenchymal cell neoplasm.