Acute exacerbation, low magnification
Acute exacerbation, low magnification

At low magnification, the image shows extensive fibrosis and loss of alveolar parenchyma. Microscopic honeycomb foci are present (circle). Left of center there is a lobule without fibrosis, but now involved with acute injury. Increased numbers of fibroblastic foci can be seen all around the edges of the preexisting fibrosis (black arrows). Click to next image for higher magnification.