Medical impact of the screening of asbestos-related benign pleural lesions.

Asbestos-related benign pleural lesions can involve the parietal pleura (pl eura plaques), and/or visceral pleura a as focal or diffuse (diffuse pleura l thickening) fibrosis. Benign asbestos pleurisy and rounded atelectasis ar e linked with visceral pachypleuritis, the former as a cause, the latter as a consequence. The prevalence of these lesions, particularly pleural plaqu es, is very high, reaching 25% in populations of workers exposed intermitte ntly to asbestos. Conventional radiology has a sensitivity less than 50 % f or detection of plaques, and a specificity less than 85 %. Tomodensitometry is today the reference diagnostic tool: availability, cost and irradiation have to be considered before its use in mass screening. Pleural plaques ar e most often asymptomatic and a functional impairment cannot be proven usua lly an an individual basis. Visceral pleural thickening is more often accom panied by symptoms (dyspnea, pain) and functional impairment. There is no t reatment susceptible to produce a regression of pleural lesions. Asbestos e xposure increases the risk of pulmonary and pleural cancers. However there is no evidence of an increased risk in subjects with plaques compared with subjects without plaques but an equivalent asbestos exposure. The cost and the risk of diagnostic procedures induced by the screening, as well as the anxiety provoked by the detection of radiologic abnormalities are to be con sidered. Finally it is difficult today to justify the screening of benign p leural lesions by arguing an improvement of the life expectancy or of the q uality of life of former asbestos exposed workers. It is probable that bene fit of a screening will be of a social type, at an individual or a collecti ve level.