RB-ILD pathology
RB-ILD pathology

At scanning magnification the biopsy shows two adjacent bronchovascular bundles, each of which has respiratory bronchiolitis (within the circles). The alveoli show variable size with some collapse (hypo) and areas of hyperinflation from air trapping (hyper). Dense pigmented macrophages (arrow) are present in the alveoli in the vicinity of the respiratory bronchioles. There are more macrophages than would be expected for respiratory bronchiolitis alone, and less than would be seen in desquamative interstitial pneumonia, where the entire biopsy would be dominated by alveoli filled with the "smokers-type" alveolar macrophages. Click to next image for higher magnification.