1. H&E-stained section from a tumor with nearly monomorphic round nuclei and an eosinophilic cytoplasm without clearly visible cell membranes; Magnification x100;
2. Tumor from picture 1 with some cells with PAS-positive round structureless cytoplasmic inclusions - secretory meningioma CNS WHO Grade 1; Magnification x100;
3. H&E-stained section from a tumor with high cellularity and more than 4 mitoses per 10 high power fields (HPFs) -atypical memingioma CNS WHO Grade 2, Magnification x400;
4. Tumor from picture 3 with brain invasion, brain tissue is GFAP-positive; Magnification x100;
5. Tumor from picture 3 with high proliferation activity; Ki67 (MIB1)-IHC; Magnification x400;