[Pleuropulmonary tumors. Presentation of 2 cases with peculiar clinicopathologic traits].

A pseudomesotheliomatous adenocarcinoma, which is a rare form of peripheral pulmonary tumor with diffuse thickening of the pleural cavity mimicking a mesothelioma, and a malignant mesothelioma with a carcinoma like disseminating pattern are presented. The biopsy obtained by thoracotomy in one case, and the necropsy studies enabled the diagnosis by the microscopic pattern, the presence of mucosubstances (PAS diastase) and the immune histochemical profiles with antibodies against several antigenic groups (CEA, EMA, CAM 5.2, and Vimentin. The value of these techniques to differentiate adenocarcinomas and mesotheliomas is discussed. The presence of CEA orients to an epithelial origin of a neoplasia.