Figure 5.

Immunohistochemical detection of ovarian microvessels in laying hens with and without ovarian cancer. Paraffin sections were immunostained with monoclonal anti-smooth muscle actin. A, Section of a hen’s normal ovary. Immunopositive microvessels are shown in the follicular theca and few in the adjacent stroma. Most of the immunopositive vessels have a thick wall. B, Section of a hen’s ovary with early-stage ovarian cancer (ovary shown in Figure 4A). Compared to the normal ovary, more immature immunopositive microvessels with leaky, thinner, incomplete, or discontinuous vessel walls are present between tumor glands. The fibrous connective tissues of the tumor glands are also stained positive. C, Section of an ovarian tumor from a hen with late-stage ovarian cancer (ovary shown in Figure 4C). Compared to the normal ovary and early-stage ovarian cancer, many leaky and immature microvessels with discontinuous or attenuated staining are seen in the vicinity of the tumor. Arrows indicate examples of immunopositive microvessels; dotted circles, examples of tumor glands; F, follicle; G, granulosa layer; S, stroma; and T, theca layer.