间变性少突胶质细胞瘤

This glioma has focal tumor necrosis and moderate degree of nuclear pleomorphism. Some cells have oval small nuclei with perinuclear halos, while others have eosinophilic fibrillary cytoplasm and processes. In the absence of classic features of oligodendroglioma, I would still favor astroctytoma. More importantly is to count mitotic figures, look for vascular/endothelial proliferation, eosinophilic granular bodies, dysplastic neurons, Rosenthal fibers and biphasic growth pattern to exclude differential diagnoses of ganglioglioma and pilocytic astrocytoma. If mitoses are easily found and no other characteristic features are identified. this would qualify as WHO grade IV glioblastoma.