Pulmonary disease associated with pleural "asbestos" plaques.

The diagnosis of asbestos-related pulmonary disease is frequently based in part on the identification of pleural plaques; however, postmortem observations have suggested that pleural plaques may occur without associated pulmonary disease. To examine this issue, we compared the pulmonary parenchymal pathology in 93 patients with pleural plaques to 93 control patients matched for age, race, and sex, all autopsied at The Johns Hopkins Hospital between Jan 1, 1981 and March 31, 1986. Pulmonary sections were graded without knowledge of the patient's group for peribronchiolar fibrosis, other types of fibrosis, emphysema, and pleural changes. Correlations were found between the presence of pleural plaques and peribronchiolar fibrosis (p less than 0.001), alveolar fibrosis (p less than 0.05), large scars (p less than 0.02), scar-related emphysema (p less than 0.02), and pleural thickening (p less than 0.005). A history of smoking was also associated with pleural plaques (p less than 0.05). Interstitial fibrosis was not significantly different between the two groups. Peribronchiolar fibrosis was neither universally nor exclusively present in patients with pleural plaques, being found in 49 (53 percent) of 93 subjects with and 36 (39 percent) of 93 subjects without plaques. The results suggest that caution must be exercised in extrapolating from the identification of pleural plaques to a diagnosis of asbestos-related pulmonary disease.