[Case of benign asbestos pleurisy with diffuse pleural thickening confirmed on autopsy]

We report a 65-year-old man with a 35-year history of occupational asbestos exposure. He presented at a nearby hospital with a complaint of dyspnea in 2002. Bilateral pleural effusion was revealed on a chest x-ray film. Chest CT revealed diffuse thickening of the pleura, bilateral pleural effusions and cardiac effusion, but no abnormal findings in the lung fields. Both pleural effusions were exudative, and lymphocytes were predominant. Antituberculous chemotherapy had no effect on the exudates. Thoracoscopic pleural biopsy was conducted to exclude malignant mesothelioma. No evidence of malignancy was found in pleural samples. The patient's condition was diagnosed as benign asbestos pleurisy with diffuse pleural thickening. He was referred to our hospital in June 2008. Bilateral pleural effusions continued to progress despite pleurodesis and frequent drainage of his pleural effusion. He suffered from respiratory failure and died in December 2008. We investigated the concentration of asbestos bodies in his lung tissue. There were 462 asbestos bodies per 1 g of dry lung tissue, which was relatively low considering the time of asbestos exposure. We report a rare case of benign asbestos pleurisy with diffuse pleural thickening confirmed by autopsy.