In the core needle biopsy specimens the lung tissue largely preserved its preexisting architecture. Histologic findings included an inflammatory infiltrate consisting of neutrophils and lymphocytes, and only a sporadic intra-alveolar fibroblastic plug. The striking, distinctive feature of this case was the presence of thin, delicate hyaline membranes along the alveolar wall (Fig. 2C). Again, micro thrombi were observed in this case. No fungi could be demonstrated in the PAS-D stain. Together with the clinical characteristics, these histologic findings were suggestive of diffuse alveolar damage.