Fig. 3From: The clinicopathological significance of angiogenesis in hindgut neuroendocrine tumors obtained via an endoscopic procedureVariation in microvessel density among tumors. Legend: a In this tumor, there are few CD31-positive endothelial cells and the tumor has an extremely low microvessel density. No venous invasion was observable (immunohistochemistry for CD31; original magnification, ×100, scale; bar represents 100 μm). b In this tumor, numerous CD31-positive endothelial cells were observable and the tumor has a high microvessel density. This is representative of most of cases with venous invasion (immunohistochemistry for CD31; original magnification, ×100; scale bar represents 100 μm)Back to article page