Figure 5

Characterization of Type II and Type III lesions. (A–F) Type II lesions. A H&E staining of a typical multicentric bubble shaped Type II lesion showing pulmonary acini totally occluded with neutrophils and karyorrhectic debris. “K”: karyorrhectic debris, “*” necrosis area. B Higher magnification of A showing necrosis areas (*) surrounded by neutrophilic karyorrhectic debris (“K”) interspersed by foamy macrophages (black arrows). C, D Immunohistochemical staining with Ab against Ly-6G (clone 1A8) showing the dense neutrophilic composition of the multicentric bubble shaped Type II lesion with aggregates of neutrophil-derived karyorrhectic debris (“K”). E Masson-Goldner’s Trichrome staining of the same area as A showing few scattered discontinuous fibrous capsule areas (#). F Ziehl staining of the same area as B showing dense acellular bacilli concentration within the karyorrhectic debris (“K”) and the necrotic areas (*) surrounded by bacilli-rich foamy macrophages (black arrows). G–I Type III lesions. G, H H& E staining of Type III lesions showing a characteristic perivascular and peribronchial inflammatory infiltrate, typical of a lymphocytic “cuffy” pneumonia, composed of foamy macrophages (black arrows) interspersed with epitheliod cells and a large number of lymphocytes scattered or in cluster (white arrow). I, J Immunohistochemical staining with Ab against Ly-6G (clone 1A8) showing the low representation of neutrophils within Type III lesion infiltrate (black arrows: neutrophils). Scale bars: 50 μm (B, F, G, J); 100 μm (A, C, D, E, H, I).