
1. H&E Section from tumor with high cellularity and palisading necroses; Glioblastoma IDH-Wildtype CNS WHO Grad 4; Magnification x40.

2. GFAP-positive tumor cells in the pseudopalisades around necrosis and a lot of GFAP-negative microvascular proliferations (tumor from Picture 1); Magnification x100.

3. High proliferation activity; Ki67 (MIB1) IHC; Magnification x400.

4. Multinucleated bizarre cells in a high grade glial tumor; H&E stain; Magnification x 200.

5. The reticulin-stain shows reticulin-free islands, which are GFAP-positive.

6. Gliosarcoma IDH-Wildtype CNS WHO Grade 4; Magnification x 40 (both pictures).