Fig. 3

B4 and C10 ISS cells form sarcomas in a murine xenograft model. a. Sarcoma that formed at site of injection of 5 million B4 cells; this is tumor B4–2 (see Fig. 2). The tumor is composed of neoplastic spindle-shaped cells arranged in streams and bundles. The cells have moderate amounts of foamy to fibrillar cytoplasm and oval nuclei with finely stippled chromatin and 1–3 prominent nucleoli. Anisocytosis and anisokaryosis are moderate and there are 0–2 mitotic figures per 400x field. Hematoxylin and eosin staining; Bar = 200 µm. Inset bar = 60 µm. b. Sarcoma that formed at the site of injection of 5 million C10 cells; this is tumor C10–1 (see Fig. 2). The tumor is composed of polygonal to spindle-shaped neoplastic cells arranged in sheets and interlacing streams, interspersed with small aggregates of eosinophilic fibrillar material (collagen). The cells have moderate amounts of fibrillar cytoplasm and oval nuclei with finely-stippled chromatin and 1–2 prominent nucleoli. Anisocytosis and anisokaryosis are moderate and there is one mitotic figure per 400x field. Admixed with the neoplastic cells are peripheral infiltrates of lymphocytes. In less than 20% of the section, neoplastic cells have shrunken or fragmented nuclei (necrosis). Hematoxylin and eosin staining; Bar = 200 μm. Inset bar = 60 μm