Figure 5a. Photomicrographs of the lesion (b [original magnification, x600; hematoxylin-eosin stain] is a magnified view of the boxed area in a [original magnification, x100; hematoxylin-eosin stain]) demonstrate regions of necrosis (white arrows) surrounded by rings of pseudopalisading tumor cells (black arrows), which are in turn surrounded by abundant microvascular hyperplasia (arrowheads).