Improved diagnosis of glioblastoma, IDH-wildtype, metastasis through molecular and DNA methylation profiling: Two case reports.

Abstract

Glioblastoma, the most common primary malignant brain tumor in adults, accounts for approximately 50% of primary malignant brain tumors. Extracranial metastases are extremely rare, affecting <0.5% of patients. This article describes two cases where Next-Generation Sequencing and DNA methylation profiling, confirmed extracranial metastases of glioblastoma, IDH-WT. The first case involves a 77-year-old man who developed lung and liver mass within months of diagnosis. While both biopsies revealed undifferentiated malignant tumor, identical genetic mutations on the lung biopsy and DNA methylation profiling on the liver biopsy confirmed glioblastoma metastases. The second case details a 75-year-old women diagnosed with glioblastoma, IDH-WT who presented diffuse bone infiltration. Bone marrow aspirate and bone marrow biopsy associated with NGS and methylation profiling confirmed glioblastoma metastasis. Both patients succumbed within 8 months. These cases underscore the importance of molecular diagnostics in identifying glioblastoma metastases and guiding treatment, particularly in rare presentations involving extracranial spread.