Extracranial metastases of high-grade glioma: the clinical characteristics and mechanism

BACKGROUND: This presentation of two cases and literature review discusses the epidemiology, clinical manifestations, pathogenesis, diagnosis, treatment, and prognosis of high-grade glioma with extracranial metastases. METHODS: A retrospective analysis of the clinical features of two cases of malignant glioma, including metastatic sites, pathological data, and treatment methods, and a literature review was performed. RESULTS: Two patients developed extracranial metastases within 1 year after surgery for primary glioma. One patient developed cervical lymph node and bone metastases while the other developed bone metastases, and both patients died within 2 months after the diagnosis of the extracranial metastasis. CONCLUSION: Extracranial metastases may develop from malignant gliomas. According to the literature, the most common extracranial site is intraspinal (along the neural axis), followed by the vertebrae, lungs, liver, and lymph nodes. The complex metastatic mechanism remains unclear, and the prognosis is very poor, with a survival duration of less than 6 months.