Gliosarcoma with Primary Skull Base Invasion

Figure 4

(a) The hematoxylin and eosin-stained histological sections showed an infiltrating glioma containing microvascular proliferation (arrow) and foci of necrosis surrounded by vaguely pseudopalisading tumor cells (“N”), diagnostic of glioblastoma. (b) Other areas showed a malignant mesenchymal component admixed with the glioblastoma. (c) The GFAP stain highlights the glial component and is negative in the mesenchymal component. (d) In contrast, the reticulin stain demonstrates extensive pericellular deposition of collagen fibers in the mesenchymal component only and is negative in the glial component. These findings support the diagnosis of gliosarcoma (all images at 100x magnification; scale bar = 300 μm).

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