Microfoci of malignant progression in diffuse low-grade gliomas: towards the creation of an intermediate grade in glioma classification?

Low-grade gliomas (GII) inescapably progress to high-grade gliomas (GIII). The duration of this transition is highly variable between patients and reliable predictive markers do not exist. We noticed in a subset of cases of GII, obtained by awake neurosurgery, the presence of microfoci with high cellular density, high vascular density, or minimal endothelial proliferation, which we called GII+.