[Carcinoembryonic antigen in pleural effusion. Adenocarcinoma versus mesothelioma].

One hundred and thirty six patients presenting pleural effusion and whose diagnosis was obtained by clinical, biochemical, bacteriological, cytological and histological methods have been studied and classified into seven groups: 20 transudates, 29 inflammatory, 25 tuberculosis, 25 non adenocarcinoid neoplasias, 24 adenocarcinomas, 10 mesotheliomas and 3 miscellaneous. Carcinoembryonic antigen was determined in all of them, evaluating as positives those values above 10 ng/ml, value which we consider discriminatory in our series and which agrees with the literature, finding positive values in 21 out of 24 adenocarcinomas and 3 out of 25 non adenocarcinomas. All benign pleural effusions and mesotheliomas had values lower than 10 ng/ml. The specificity to determine adenocarcinomas in neoplastic effusions was 91.48% and the sensibility was 87.5%. We consider that the CEA determination is useful to differentiate adenocarcinomas from other neoplasias and that a positive value rules out mesothelioma.