Radiologic-pathologic correlations of small lung nodules with special reference to peribronchiolar nodules

A radiologic and pathologic correlation has been made of small lung nodules. At necropsy 100 excised lungs were fixed and slices from them radiographed. The radiographs were used to select individual nodules for histologic study. Nodules in bronchopneumonia, acinonodose tuberculosis, chronic bronchiolitis, and simple pneumoconiosis due to ferric dust were shown to be located around inflamed terminal or respiratory bronchioles. Intraacinar infiltration was usually diffuse, but when nodules were seen, they occurred in peripheral airspaces with no relation to bronchioles. Hematogenous metastases showed distinctly marginated nodules, some truly intraacinar. Although each type of nodule can appear as an "acinar" or "subacinar" image on chest radiographs, this radiologic-pathologic study shows that they differ significantly in their relation to the airway structures.