ABSTRACT
Pleural fluid is occasionally found to be milky, whitish, opalescent, or at least turbid. This appearance is sometimes due to a high lipid content in the pleural fluid. Two different conditions are characterized by the accumulation of high levels of lipid in pleural fluid. In one, chyle enters the pleural space as a result of disruption of the thoracic duct, producing a chylothorax or a chylous pleural effusion. In the second, large amounts of cholesterol or lecithin-globulin complexes accumulate in a long-standing pleural effusion, producing a pseudothylothorax or a chyliform pleural effusion. Apart from the appearance of the pleural fluid, these two conditions have nothing in common. They have completely different prognosis and management.
