A case report about extracranial skeletal metastases in pediatric diffuse midline glioma, H3 K27-altered

We report a rare case of diffuse midline glioma, H3K27-altered (DMG), with extracranial metastases in a 9-year-old boy. The patient, initially treated with standard chemoradiotherapy, developed radiographically confirmed vertebral and peritoneal metastases within several months. Despite aggressive therapy, survival was short, underscoring the dismal prognosis associated with extraneural dissemination in DMG. Characteristic imaging findings and potential mechanisms of metastasis are discussed. This case highlights the need for early recognition and comprehensive systemic evaluation in managing atypical metastatic patterns of DMG.