Figure 10b. T1 adenocarcinoma with vascular invasion in a 66-year-old man. (a, b) Transaxial thin-section CT scans (lung window) obtained at the levels of the main bronchi (a) and right upper lobar bronchus (b) show a 20-mm nodule with a lobulated margin and thickened bronchovascular bundles in the right upper lobe (arrow). (c) Low-power photomicrograph (original magnification, x4; H-E stain) shows tumor invasion of adjacent bronchovascular bundles (arrows).