[A case of diffuse malignant mesothelioma diagnosed by thoracoscopic biopsy]

We report a case of diffuse malignant mesothelioma discovered by thoracoscopic examination undertaken while formulating a preoperative diagnosis. A 61-year-old male complained of coughing and sputum production, and was admitted because his chest roentgenogram indicated an abnormal shadow. Chest CT scanning demonstrated right pleural effusion and multiple nodules sited on the diaphragm. Because aspiration biopsy of such nodules was difficult, we performed a thoracoscopic examination. The thoracoscopic findings demonstrated bloody pleural effusion in the right thoracic cavity and multiple nodules on the diaphragm, parietal and pulmonary pleura. They were white and 0.5 to 2 cm in size. By excisional biopsy, these were diagnosed as epithelial-type diffuse malignant mesothelioma. We therefore performed panpleuropneumonectomy. Even though we completely resected the canal of thoracoscope and drainage tube, microscopic findings showed invasion of mesothelioma cells into this thoracoscopic canal. Although we suggest that, in preoperative diagnosis of pleural tumor, thoracoscopy is efficient to perform a pathological examination and confirm the extension of tumor, in the actual operation, we believe that the thoracoscopic canal should be resected.