Figure 8b. BAC in a 45-year-old woman. (a) Transaxial thin-section (1-mm collimation) CT scan (lung window) obtained at the level of the basal segmental bronchi shows a 13-mm nodular area of ground-glass attenuation in the right lower lobe (arrow). (b) High-power photomicrograph (original magnification, x100; H-E stain) shows the spread of neoplastic cells (lepidic growth).