Figure 2.

(A) A Hematoxylin and Eosin staining section (a lower magnification view) showing a cyst-like lesion (arrowheads) and a nodular lesion. (B) A higher-magnification view of the nodular lesion showing amorphous eosinophilic materials in the walls of small vessels (*) and perivascular interstitium (inset of A). (C) An enlarged view of inset C showing interstitial fibrosis with chronic inflammatory infiltration and enlarged airspaces, forming a cyst-like lesion. (D) The infiltration of mononuclear cells in peribronchiolar stroma leads to narrowing of the bronchiolar lumen.