Figure 2.

Pathological assessment by H&E staining in chronic immune checkpoint inhibitor pneumonitis. (A) Patient 1: bronchiolitis obliterans organizing pneumonia (BOOP), described in manuscript as organizing pneumonia, with an intra-alveolar fibroblast plug and organizing alveolar fibrin. (B) Patient 2: acute lung injury with acute fibrinous organizing pneumonia and organizing diffuse alveolar damage. (C) Patient 3: organizing alveolar fibrin consistent with exudative phase of BOOP. (D) Patient 4: organizing pneumonia (BOOP) with organizing alveolar fibrin. (E) Patient 5: organizing alveolar fibrin consistent with exudative phase of BOOP. (F) Patient 6: organizing pneumonia (BOOP). PD-1, programmed death 1.