Incidence of Pulmonary Emphysema

Abstract

mortem, the criteria for the diagnosis of emphysema were not given, and the types of emphysema not described. Only two studies are available that assess the incidence of emphysema using modern anatomic methods and current terms. The first of these, by McLean (5) of Melbourne, Australia, stated that emphysema was invariably present in adults at autopsy if emphysema associated with small scars in the lung was included. He estimated that emphysema was the primary cause of death in 2.6 per cent of 2,000 autopsies at the Royal Melbourne Hospital and that, in a further 4.1 per cent, emphysema contributed to illness. In the second study (6), centrilobular or panacinar emphysema was present in half of 50 consecutive autopsies on adult males at the Hammersmith Hospital in London, England. The first objective of the study reported here was to assess the incidence of emphysema in a random group of necropsies using modern terminology and methods. I t is generally agreed that centrilobular emphysema. (figure 1) and panacinar emphysema (figure 2) are the most important forms of emphysema. Excellent illustrations of these conditions are available in a Ciba Symposium report (7), as well as in the reports listed below, and may be of interest to readers unfamiliar with them. Although the morphology of these two forms of emphysema is well described, their relative frequency and respective sites of predilection within the lung are matters of dispute. For example, some writers are of the opinion that panacinar emphysema occurs as frequently as centrilobular emphysema (3, 8); others, that panacinar is more common (6, 9); and others, that it is less common (5, 10). Panacinar emphysema is variously described as occurring diffusely through the lung (g), accentuated in the upper part of the lung (3), the lower lung (8), or the lingula and middle lobes (5). Centrilobular emphysema is described as involving predomi-