Pneumonia, Viral

Adult respiratory distress syndrome (ARDS)

High magnification of exudative stage of ARDS showing hyaline membranes, large atypical type 2 pneumocytes, and inflammatory cells. The alveolar structures are obscured by the intense inflammatory infiltrate.

Gross figure showing chronic aspiration pneumonia with organizing bronchopneumonia and extensive bilateral fibrosis, characterized by grayish-white areas at the lung periphery, with the only normal lung tissue appearing dark brown.

Organizing acute pneumonia with fibroblastic proliferation filling airspaces and a mild lymphocytic infiltrate.

FIGURE 1.26. A 40-year-old man who developed a left pneumothorax while being ventilated for acute respiratory distress syndrome (ARDS). A: Baseline chest radiograph shows diffuse parenchymal airspace opacity compatible with ARDS. B: A chest radiograph obtained during respiratory deterioration shows a new lucency over the region of left hemidiaphragm (deep anterior sulcus). There is also increased depth of the lateral costophrenic sulcus. The thin white line of pneumothorax is evident superi...

FIGURE 26.3. High-resolution computed tomographic image of basal regions of the lungs in organizing pneumonia associated with rheumatoid arthritis. Diffuse but patchy "ground-glass" opacities are well seen.

FIGURE 29.8. High-resolution computed tomography. Peripheral subpleural patchy areas of alveolar opacification. Air bronchograms are evident (idiopathic bronchiolitis obliterans-organizing pneumonia).

FIGURE 29.12. High-resolution computed tomography. Peripheral subpleural nodular opacity in a histologically proven case of idiopathic bronchiolitis obliterans-organizing pneumonia.

FIG. 11.27. Pneumonia with large pleural effusion. This child presented with bacterial pneumonia and respiratory distress, presumed to be caused in part by the large pleural effusion. In the emergency department, a pleural catheter ("pigtail") was placed for drainage, using the Seldinger technique.

FIG. 11.61. Varicella pneumonia. Severe pneumonia developed in this patient shortly after she developed vesicular skin lesions that were positive for varicella-zoster virus by direct fluorescent antibody. Varicella causes a diffuse, miliary pattern.

Bronchiolitis obliterans with organizing pneumonia (BOOP). Polypoid plugs of loose fibrous tissue are present in a bronchiole and the adjacent alveolar ducts and alveoli.

FIG. 16.2. Hyaline membrane disease and bronchopulmonary dysplasia. Hyaline membrane disease. This is one of twins born at 31 weeks' gestation. The chest radiograph shows hypoaeration, diffusely opaque lung fields, air bronchograms, and loss of normal vascular shadows.

Diffuse alveolar damage (adult respiratory distress syndrome, ARDS). In ARDS, type I cells die as a result of diffuse alveolar damage. Intra-alveolar edema follows, after which there is formation of hyaline membranes composed of proteinaceous exudate and cell debris. In the acute phase, the lungs are markedly congested and heavy. Type II cells multiply to line the alveolar surface. Interstitial inflammation is characteristic. The lesion may heal completely or progress to interstitial fibrosis.