Figure 3.

Photomicrographs of anaplastic oligodendroglioma and arteriovenous malformation (AVM) histology (a) anaplastic oligodendroglioma showing uniform cellularity, uniformly round nuclei, and perinuclear halos. This section shows classic delicate microvasculature, although microvascular proliferation was seen in other areas. Inset highlights an atypical mitotic figure of which many were identified (H and E; original magnification, ×200). (b) Secondary features of oligodendroglioma include scattered microcalcifications (center of the image) and clonal nodules of heightened cellularity (right side of image) (H and E original magnification, ×100). (c) Irregular large vessels of the AVM with intervening cellular oligodendroglioma (*) (H and E original magnification, ×20). (d) Irregularly contoured vessels of the AVM filled with black granular embolization material. An intimal cushion is identified in one of the fibrotic vessel walls (*) (H and E original magnification, ×50)