Source:http://linkedlifedata.com/resource/umls/id/C0032326
MSH: An accumulation of air or gas in the PLEURAL CAVITY, which may occur spontaneously or as a result of trauma or a pathological process. The gas may also be introduced deliberately during PNEUMOTHORAX, ARTIFICIAL.,CSP: accumulation of air or gas in the pleural space, which may occur spontaneously or as a result of trauma or a pathological process.,NCI: A disorder characterized by abnormal presence of air in the pleural cavity resulting in the collapse of the lung.,NCI: Abnormal presence of air in the pleural cavity.