Carcinoembryonic Antigen Levels in Benign and Malignant Pleural Effusions

Abstract

Unselected fluid specimens (191) submitted routinely for cytologic examination were assayed to determine whether the measurement of carcinoembryonic antigen (CEA) levels in human pleural effusions is useful in detecting malignancy. The mean .+-. SD CEA level of 103 benign effusions was 4.1 .+-. 2.9 ng/ml. Only 1 benign effusion had a level > 12 ng/ml (18 ng/ml). Benign inflammatory effusions (pneumonia, empyema) had a higher mean CEA activity (6.2 .+-. 3.4) than effusions caused by congestive heart failure (2.9 .+-. 1.5) (P < 0.001). Twenty-four (34%) of 70 malignant effusions had a CEA level > 12 ng/ml, and 28 (40%) were positive by cytologic study. Thirty-eight (54%) were detected by 1 or both methods. Ten malignant effusions were positive by CEA (> 12 mg/ml) alone. The determination of CEA activity levels, when used in conjunction with other clinical findings, may be useful in detecting malignant pleural effusions.