Glioblastoma multiforme involvin

This slide shows spread of a glioblastoma to the cerebellum. The diagnosis of GBM is not clearly evident from this slide, but this is from the same patient as the slide showing the necrosis, so the diagnosis is known. The most significant finding in this image is the area highlighted in green: what looks like infant external granular cell layer is actually subpial spread of tumor cells. This person was not an infant. It is also interesting to note that there is a paucity of Purkinje cells in the Purkinje cell layer (unnecessarily large red arrow).