A 67-year-old female patient with lung adenocarcinoma and a negative spread through air spaces (STAS) status. (Figure 14) The axial non-contrast computed tomography image shows a mixed ground-glass nodule in the right lower lobe of the lung, with the longest interface length of the entire tumor and solid component being 1.80 cm and 5.57 mm, respectively; consolidation-to-tumor ratio <50%, with an irregular shape and a well-defined interface. (Figure 15) The pathological section indicated a negative STAS status; that is, there were no free tumor cell clusters in the alveolar cavity outside the edge of the main lesion. The photomicrograph (hematoxylin and eosin stained, magnification x40) shows clean alveolar spaces adjacent to the boundary (dashed line) of the tumor (star).