Laennec first described pulmonary emphysema from observations of the cut surface of necro- scopic human lungs that had been air dried in
inflation.1 He attributed the lesions to atrophy of
lung tissue resulting from overinflation, and this
hypothesis appeared in a major textbook of
pathology as late as 1940.2 Emphysema was redefined as “abnormal permanent enlargement of
airspaces distal to terminal bronchioles”,3 and
this definition was modified to include “destruction of alveolar walls without obvious fibrosis”.4
McLean5 and Leopold and Gough6 implicated the
inflammatory response in the pathogenesis of the
centrilobular form of emphysema, but this
suggestion was interpreted conservatively because their studies were based on necroscopic
specimens that were frequently contaminated by
terminal bronchopneumonia