Figure 1.

Microscopic features of micropapillary component in the lung adenocarcinoma stained with hematoxylin-eosin (HE). A, AMPC. AMPC is the micropapillary component in which tumor cells are floating within alveolar spaces. B, SMPC. SMPC are tumor cells observed in the stroma and consisting of a papillary component with a tuft lacking central fibrovascular cores surrounded by lacunar spaces. (A, B: upper panel: magnification, ×100; lower panel: magnification, ×400) SMPC, stromal micropapillary component; AMPC, aerogenous micropapillary component.