Fig. 3

Images in a 46-year-old patient with minimally invasive adenocarcinoma (a~c) and a 72-year-old patient with invasive adenocarcinoma (d~f). a The lung window of the axial HRCT image shows a part solid nodule in the right middle lobe. b The CT number distribution curve presents the solid component proportion of the nodule at 0.9%. c Photomicrograph (haematoxylin and eosin stain; magnification × 5) shows minimally invasive adenocarcinoma primarily comprising lepidic growth with a small (1.64 mm) central area of invasion. d The lung window of the axial HRCT image shows a solid nodule surrounded by a few ground-glass-opacity nodules in the right middle lobe. e The CT number distribution curve presents the solid component proportion of the nodule at 54.5%. f Photomicrograph (haematoxylin and eosin stain; magnification × 200) shows acinar predominant invasive adenocarcinoma primarily comprising 70% acinar pattern, 15% lepidic pattern and 15% papillary pattern