Fig. 4

Representative HE-stained images of a) adenocarcinoma in situ (AIS), b) minimally invasive adenocarcinoma (MIA), and c) lepidic predominant invasive adenocarcinoma (LPIA). In AIS, no foci of invasion or scarring could not be seen, and atypical pneumocytes were proliferating along the slightly thickened alveolar wall. In MIA, showing a small area of invasion (<0.5 cm), tumor cells grew mostly in lepidic pattern along the surface of alveolar walls. In LPIA, showing a larger area of invasion (≧0.5 cm), type II pneumocytes and Clara cells were proliferating along the surface of thickened alveolar walls. Alveolar epitheliums are substituted in tumor cells, together with examples of targeted lesions before and after laser-microdissections (LMD)