Asbestosis: VI. Analysis of Forty Necropsied Cases

Abstract

Forty necropsied cases of human asbestosis have been analyzed and certain findings related to uncleared questions are here presented. In this series occurs evidence that the disease does not progress beyond a limited time after exposure to asbestos dust ceases, although the fibrosis caused persists and ages into dense scar tissue. In minor grades of the disease, there is little to indicate any recognizable influence. Characteristically some other unrelated condition caused the fatal disease. In practically all such cases the state of asbestosis was undiagnosed until disclosed at necropsy. This was likewise true in most of those of medium grade lung damage. Only in advanced form was asbestosis a conspicuous state and in only a part of those of that grade was it a major event or the sole factor in the fatal disability. Asbestosis bodies remain deposited in the lung indefinitely, at least as long as twenty-seven years. In old deposits they show some evidence of change. Smaller forms do occur in peribronchial lymph nodes. Pleural involvement as a part of the disease is not constant nor essential. It is indicated as of secondary occurrence. Local fibrous nodular lesions comparable to those characteristic of silicosis occurred in such prominence as to question whether they may not also be produced by asbestos. Carcinoma of the lung was also of such prominence as to require continued consideration as possibly inducible in a susceptible subject by severe asbestosis until disproven by further investigation. Although tuberculosis of the lungs occurred with more frequency than in the general necropsy series, careful analysis of pertinent evidence does not add much weight to the idea of relationship, while some evidence occurred that improvement of tuberculosis may proceed in the face of advancing asbestosis in at least one case.