Fig. 4.

Organizing pneumonia in a 56-year-old woman with dermatomyositis.

(a, b) Lung window images of CT scans obtained at levels of liver dome (a) and 3 cm inferior to a (b), respectively, show patchy distribution of consolidation along bronchovascular bundles (arrows) and subpleural lungs (open arrows) in both lungs. (c) Coronal reformatted image demonstrates consolidation along bronchovascular bundle (arrows) and subpleural (open arrows) lungs. (d) Low power magnification of lung demonstrating organizing pneumonia (arrows) transitioning to fibrotic NSIP (arrowheads). CTD is in the etiologic differential of fibrotic NSIP, but there are no histologic findings in this image that suggest CTD as the underlying cause in contrast to the lymphoid follicles with reactive germinal centers seen in Fig. 1, Fig. 2.