The relationship between radiographic and pathological appearances of progressive massive fibrosis

A preliminary comparison has been made between a radiographic and a pathological classification of progressive massive fibrosis (PMF) in 73 coalworkers. All of the men had PMF at autopsy and a chest radiograph taken within four years of death. In 57 of the men the PMF appeared as large opacities of homogeneous radiodensity on the radiograph (type 1). Only two of the five other possible types of PMF were observed. The three pathological types were equally represented within radiographic type 1. The proportion of the area of the cut surface of the lung occupied by PMF lesions was significantly greater for radiographic type 1 PMF than for any other. In five of the six men with a radiographic type of PMF consisting of conglomerations of small rounded opacities (type ‘r’ on the ILO scale) the pathological appearance was of lesions formed by aggregation of fibrotic nodules. The predominance in this series of the radiographic PMF type 1, a relatively non-specific appearance may be a consequence of using radiographs taken near to death.