Routine diagnostic tools of formalin-fixed and paraffin-embedded tumor samples of diffusely infiltrating HGG should at least include a hematoxylin and eosin (H&E) staining and a reticulin silver staining as well as immunohistochemical examination with antibodies against glial fibrillary acidic protein (GFAP), p53 and Ki67 (Mib-1). Here, GFAP is linked to neoplasm.