Emphysema is an enlargement of air spaces caused by destruction of alveolar walls.
Air spaces greater than one cm are bullae.
This photo shows apical bullous disease with relatively little involvement of the rest of the lung. This lung shows centriacinar emphysema with holes located around the terminal bronchioles and preservation of more distal air spaces. The parenchyma along the major fissure shows some distal acinar emphysema. Panacinar emphysema involves the entire acinus. Centriacinar emphysema This section of centriacinar emphysema shows the enlarged air spaces around a small airway.