Fig. 3: Fibrotic hypersensitivity pneumonitis (HP).

A Several Schaumann bodies with a giant cell in the same field as Fig. 2D. Schaumann bodies are, effectively, tombstones of granulomas and provide the same diagnostic information. B Patient with household mold exposure. In this case the pattern is that of fibrotic nonspecific interstitial pneumonia (NSIP). C Higher power view of figure 11 showing granulomas (arrows) which indicate that this is really fibrotic HP and not NSIP. D Patient with hot tub exposure. In this lobe the biopsy is a perfect mimic of usual interstitial pneumonia/idiopathic pulmonary fibrosis.