Pattern recognition in radiographs of excised air-inflated human lungs. III Chronic interstitial and granulomatous inflammation, scars and lymphangitis carcinomatosa in non-emphysematous lungs.

To evaluate the patterns of chronic interstitial and granulomatous inflammation, scars and lymphangitis carcinomatosa in radiographs of excised air-inflated lungs at autopsy, the distribution of these findings in 89 lungs was determined histologically on 441 sections sampled systematically. Pathologic-radiologic correlations were studied on the basis of 29 sections from 18 lungs selected to represent unequivocally the features in question. Chronic interstitial pneumonia exhibited uneven, trabecular or macular densities distributed randomly. Honeycomb lung was characterized by a coarse reticular pattern with fairly regular and roundish translucencies measuring 2-20 mm in diameter. Granulomas of miliary tuberculosis and sarcoidosis appeared as roundish macular densities, 2-5 mm in diameter. The former were randomly distributed while the latter seemed to follow lobular septa. Scars appeared as randomly distributed, either trabecular, star-shaped or polygonal densities. Several larger scars contained calcified foci. Intraparenchymal scars of at least 2 mm in diameter, and even smaller subpleural scars, were visible radiographically. Lymphangitis carcinomatosa appeared as unevenly thick linear opacities.