ROUND ATELECTASIS AND ASBESTOS - A REVIEW OF 26 PATIENTS

Round atelectasis (AE) is a benign form of respiratory problem which d evelops due to fixing of the visceral pleura. This lesion for which th e principal cause is exposure to asbestos may pose problems of differe ntial diagnosis with bronchopulmonary cancer. In a cohort of 286 patie nts suffering from benign asbestos related pleural disease the diagnos is of round atelectasis was made oi? computerised tomography in 26 pat ients (31 AE) on rite following criteria: rounded opacities of less th an? 7 cm in diameter situated at the periphery of the lung in contact with a thickened pleura with an acute angle linking the pleura and the opacity, a reduction of lung volume on the side of the atelectasis an d the presence of a ''comet tail sign''. These patients Mere investiga ted to specify the circumstances of rite occurrence, including their s ymptomatology, the changes in lung function, the topography of the rou nd atelectasis and the associated radiological signs. Intense exposure to asbestos either continuous or discontinuous was found in 19 patien ts; 20 patients presented with some respiratory symptoms (dyspnoea 15/ 26 cough 11/26 and chest pain 9/26) but the reduction in lung function was moderate (7 had restrictive ventilatory trouble, 4 obstructive pr oblems and a mixed problem in 1). The preferred localisation for round atelectasis was in the inferior lobes in the posterior basal lateral vertebral area (26/31) which may explain their being frequently missed on the standard radiograph (only one case of round atelectasis was vi sible on the straight chest radiograph in our study). An understanding of the pathology and the computered tomographic characteristics are n ow well defined and should enable nn unnecessary diagnostic thoracotom y to be avoided which besides has no justification from the functional point of view.