CD163 and neoplasm: Fig. 3E,F again illustrates significant differences between IBA1 and CD163 expression. IBA1 is expressed mainly in the upper half of what likely represents a cortical gyrus that is infiltrated by tumor cells. Palisading IBA1 positive microglia/macrophages (cf. Fig. 3A,B) form a demarcation line (“rim”, arrows) above the necrotic tissue area which is largely devoid of IBA1 staining but shows strong CD163 immunoreactivity in Fig. 3F. There is some accentuated CD163 staining at the rim. However, CD163 labeling is largely diffuse and most pronounced in the hypocellular tissue area (Fig. 3F).