Fig. 1

Photomicrographs of the lesion: astrocytes with nuclear atipia and mitosis (arrows) (a: hematoxylin and eosin, 40X) and high proliferation index (b, Ki-67 mmunocoloration, 10X). The surgical sample was routinely fixed in neutral buffered formol and embedded in paraffin. One 5 μm thick histological section obtained from each paraffin block was stained with hematoxylin and eosin. Further sections of the most representative paraffin block were used for immunohistochemistry and molecular analysis. Immunohistochemical studies were performed using the standard streptavidin-biotin technique and commercially available antibodies (Glial Fibrillary Acidic Protein, GFAP; p53 protein; Synaptophysin, SP; Ki-67). BRAF and H3F3 genes were analyzed as previously described [7, 8]