Results of hematoxylin and eosin staining (H&E) and immunohistochemistry from case 1. H&E staining (A) revealed a necrotic core (NC) and perinecrotic area (PN), including micro bleeding (A, arrowhead) and abnormal angiogenesis (A, arrow). Immunostaining results for PDGF-C are presented as a representative example (B). PDGF-C (C and D), D (E and F) and PDGFR-α (G) were produced by monocytic cells (C, E, G, arrow) and reactive astrocytic cells (D, F, G, arrowhead) in PN. On the other hand, PDGFR-β (H and I) was expressed mainly in endothelial cells (H and I*). There was partially nonspecific staining in NC (B) or around blood vessels (I). Original magnification, A, B and H × 40, C, D, E, F, G and I × 200.