Cerebellar glioblastoma: a clinical series with contemporary molecular analysis.

GBM located in the cerebellum can be found in all age groups. We provide novel molecular genetic data on these rare tumors. Mutated IDH1 R132H protein and H3F3A K27M mutations indicate that a substantial number of GBMc are "metastatic" or "diaschismatic" lesions. Mutation of BRAF V600E may have a stronger biological significance than H3F3A K27M alterations. In a subset of patients, GBM may arise primarily as a distinct entity in the cerebellum.