Annexin A2 Expression in the Aerogenous Spread of Pulmonary Invasive Mucinous Adenocarcinoma with Gastric Lineage

Figure 5

ANX A2 and collagen IV immunostaining of the lepidic or papillary component of the left lung tumor. (a) Tumor cells exhibit cytoplasmic ANX A2 positivity on the basal side. ANX A2 immunostain, scale bar: 400 μm. (b) A linear positive collagen IV reaction corresponding to the basement membrane is seen on the surfaces of both alveolar and vessel walls. Collagen IV immunostain, scale bar: 400 μm. (c) Detached tumor cells also exhibit cytoplasmic ANX A2 positivity on the basal side but not at the cell–cell borders. Positive staining is also observed in the exfoliative gap. ANX A2 immunostain, scale bar: 100 μm. (d) Weak or no collagen IV positivity is visible at the detachment site (arrows). Collagen IV immunostain, scale bar: 100 μm.

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