Figure 9a. Topotecan-induced organizing pneumonia in a 45-year-old woman with small cell lung cancer who presented with increasing dyspnea. (a) High-resolution CT scan shows diffuse ground-glass attenuation and septal thickening in a crazy-paving pattern in the right upper lobe (arrows). (b) Photomicrograph (original magnification, x400; hematoxylin-eosin stain) of a specimen from wedge resection biopsy of the right upper lobe shows scattered interstitial inflammation and occlusion of terminal bronchioles and alveolar ducts by plugs of loose connective tissue (*), findings typical of organizing pneumonia.