Figure 2: Histopathology of patient PF1, PF2, PF3 and PF4.
PF1: Left: high power H&E stained lung tissue showing slender alveolar septae with foamy type II pneumocytes. This was immunohistochemically confirmed with the pro-surfactant protein C staining (inset). The cells where negative with the CD68 macrophage marker (not shown). Right: more fibrous lung tissue with fibroblast foci. To a lesser extent also in these areas foamy type II pneumocytes were found.
PF2: High power H&E stained fibrotic lung tissue with a large fibroblast focus. The alveolar spaces are filled with macrophages (also right panel), consistent with DIP pattern.
PF3: Left and right: medium power H&E stained fibrotic lung tissue. The pneumocytes do not show the foamy aspect as was seen in PF2.
PF4: Left and right: medium and high power fibrotic lung tissue. Foamy macrophages were not seen. In some alveoli debris was seen, possibly associated with passed pneumonia.