257 Long Term Asbestos Exposure as a Cause of Eozinophilic Pleural Effusions

BACKGROUND: Exposure to asbestos can cause several different types of pleural disease: first diffuse malignant mezothelioma, plural plaques or calcification, loculated pleural abnormality called “rounded atelectasis” and benign pleural effusions (PE). OBJECTIVE: To determine the frequency of various pleural diseases related to asbestos exposure. METHODS: A retrospective analysis of 6 cases of PE related to the occupational asbestos exposure (AE) was made, after exclusion of other possible causes of PE. They were evaluated in the period of 7 years. RESULTS: All cases were male and almost all were more than 60 years old. All cases had more then 30 years from the first occupational AE (5 in building construction and sixt in mine). All of them reported pleuritic chest pain, or feeling heavy in their chest. The chest radiographs showed small to moderate-sized PE, which was bilateral by tree patients (pts) by the others with pleural califications in one of them. One of the pts had 3 episodes of PE and evidence of parenhimal asbestosis. PE was serous exudate and serosanguineous in 2 pts, with polymorphonuclear leucocytes, mononuclear cells and eosinophils (EO). We have evaluated the number of EO in the pleural fluid (PF), from the smear of PF colored by May-Grunwald-Giemsa. The PF differential WBC consisted predominately EO and mononuclear cells. At 4 pts more than 30% EO were found in the PF and 21% and 17% in other 2 pts respectively. During the follow up period of 3 years no other cause of PE has been found and there has been no evidence of mesothelioma in all the pts. CONCLUSIONS: Exposure to asbestos can cause PE with predominant presence of Eo cells.