Pathogenesis of shrinking pleuritis with atelectasis--"rounded atelectasis".

The pathogenesis of "shrinking pleuritis with atelectasis" or "rounded atelectasis" is discussed on the basis of 37 operated patients and on experiments on cadaver lungs. Peroperative dissections with microscopic examinations and the results of experiments with the cadaver lungs support the concept that the lesion is caused by an inflammatory reaction in the visceral layer of the pleura, caused by asbestos fibers. The inflammation occurs in stages, with deposition of connective tissue that shrinks and causes considerable atelectasis of the underlying pulmonary parenchyma. Compression of the lung due to fluid collecting in the pleural cavity involved was not noted.