No abstract

From March 1977 to December 1978, postmortem examination was performed at Wadsworth Veterans Administration Medical Center for 20 patients who had had nosocomially acquired Legionnaires' disease. Seventeen patients died during the acute illness due to Legionnaires' disease, and three patients died after clinical resolution of the acute process. The only consistent postmortem findings were limited to the lungs. Confluent bronchopneumonia, and less frequently lobar pneumonia, was present in most cases. Although a spectrum of microscopic pulmonary findings was observed, the characteristic histologic features of acute Legionnaires' disease were an extensive intra-alveolar exudation of macrophages and neutrophils in varying proportions, erythrocytes, and fibrin. Lysis of the inflammatory cells was frequently found. Areas of coagulative necrosis of the lung parenchyma and edematous thickening of the alveolar septa were typically seen. Microscopy of lung tissue from the three patients who died after clinical resolution of the acute process revealed organized pneumonia, with patchy organization of the intra-alveolar exudate and focal obliteration of the alveolar septal framework. Associated postmortem findings were fibrinous endocarditis in one case and hemorrhagic infarction of the adrenal glands in two cases. Electron-microscopic examination of the lungs revealed as many as 23 separate bacillary profiles within a single macrophage. Septate binary fission or spore-like structures were not observed.

No abstract

The light and electron microscopic features of two mixed tumors of the skin of the salivary gland type demonstrate eccrine differentiation of the epithelial component. The tumors were made up of tuboalveolar spaces lined by an eccrine duct type of epithelium with luminal cells showing numerous microvilli. The mesenchymal elements were fibroblasts and chondrocytes embedded in a mucous and chondroid matrix. Groups of undifferentiated cells without eccrine differentiation but with ultrastructural features suggestive of epithelial origin were seen among the mesenchymal and epithelial elements of the tumor.

Two cases of metastatic cystosarcoma phyllodes, one in lung and the other in axillary lymph nodes, were studied with the light and the electron microscopes. The malignant element of these tumors appears to be a poorly differentiated mesenchymal cell. No evidence supporting the presence of epithelial cells was found. The tumor metastatic to the axilla exhibited intracellular virus‐like particles similar to those described in adenocarcinoma of breast and other sarcomas.