Measured CEA in plenral fluid and serum to differentiate benign or malignant pleural effusion

Objective To discuss the function of differential diagnosis whether the pleural effusion is benign or malignant by measuring the CEA in serum and pleural fluid.Methods Serum and hydrothorax samples were collected from 96 patients with pleural effusion.Among them,36 patients were suffered with malignant pleural effusion and 60 patients with benign pleural effusion,the concentration of CEA was determined by immunoradiometric assay.Results The CEA in serum and pleural fluid benign was in normal range with ratio of CEAp/CEAs less than 1.The CEA in serum was normal or higher in malignancy,CEA in pleural fluid was higher than in normal with ratio more than 1 of CEAp/CEAs.Conclusion Tumor maker CEA has high clinical value in the differential diagnosis of pleural effusion.