Different types of tumor microvessels in stage I-IIIA squamous cell lung cancer and their clinical significance

Figure 2 Features of parenchymal and stromal tumor components. A: Loose, fine fibrous connective tissue in the tumor stroma. Scale bar = 10 μm; B: Tumor spread through the unchanged alveolar air spaces (AASs). Scale bar = 100 μm; C: Spread of the relatively unchanged clusters of tumor cells (red arrows) and the completely necrotic tumor masses (orange arrows) through the AASs having thickened walls with dilated capillaries. Scale bar = 100 μm; D: Fragmentation of the tumor masses spreading through the AASs. Scale bar = 100 μm; E: Positive nuclear expression of hypoxia-inducible factor-1 alpha (HIF-1a) in fibroblast-like tumor cells. Scale bar = 10 μm; F: Positive nuclear expression of Snail in fibroblast-like tumor cells. Scale bar = 10 μm; G: Retraction clefts. Scale bar = 100 μm; H: Structures with partial endothelial lining (orange arrows). Scale bar = 100 μm. A and G: Mayer's hematoxylin and eosin staining; B, C and H: Staining with antibodies against cluster of differentiation 34; E: Staining with antibodies against HIF-1a; F: Staining with antibodies against Snail.