Fig. 3

Photomicrographs of canine osteosarcoma growth on the chick embryo chorioallantoic membrane. a Overview of tumor growth of canine osteosarcoma cell line. H–E, bar: 200 µm; b Visible high cellularity of the tumor with pleomorphism, bizarre mitotic figures (arrows), multinucleated giant cells (thick black arrow), proliferation of small blood vessels (arrowheads). H–E, bar: 20 µm; c tumor mass composed of polygonal to spindle cells separated by fine fibrovascular matrix and showed high mitotic rate. H–E, bar: 20 µm; d basophilic deposits (thick black arrow) surrounded by osteoclast-like giant cells (arrowhead) and the infiltration of heterophils (arrow). H–E, bar: 20 μm