Figure 5.

Photomicrographs of surgical lung biopsy specimens from two different sites in a patient with fibrotic hypersensitivity pneumonitis. (A) Scanning magnification view showing multiple sections of a right-lower-lobe biopsy specimen. There is patchy fibrosis with architectural distortion, a combination of findings that resembles usual interstitial pneumonia. Magnification, 6×. (B) Low-magnification photomicrograph showing one of the sections illustrated in A, characterized by a pattern of patchy fibrosis with subpleural honeycomb change that resembles usual interstitial pneumonia. Magnification, 17×. (C) Higher-magnification view showing expansion of the peribronchiolar interstitium by a cellular infiltrate of mononuclear inflammatory cells (upper left) and isolated Schaumann bodies (arrows) at the edge of the biopsy specimen. Magnification, 46×. (D) High-magnification photomicrograph showing one of the isolated Schaumann bodies illustrated in C. Magnification, 400×. (E) Photomicrograph from another section illustrated in A showing an isolated Schaumann body (arrow) in the fibrotic peribronchiolar interstitium. Magnification, 63×. (F) Low-magnification photomicrograph of a right-middle-lobe biopsy specimen from the same patient showing features more closely resembling nonfibrotic hypersensitivity pneumonitis. There is a more cellular chronic interstitial pneumonia accentuated around bronchioles with scattered calcified Schaumann bodies (arrows) marking isolated multinucleated giant cells. Magnification, 43×. Hematoxylin and eosin staining was used. B = bronchiole.