A case of malignant mesothelioma detected hydropneumothorax.

A 61-year-old man was admitted to the emergency room because of sudden right chest pain and dyspnea. A chest X-ray and chest computed tomography (CT) revealed severe right pneumothorax with massive pleural effusion. Chest drainage was performed and approximately 1.2 L of pleural fluid was removed. Hemothorax was suspected based on the imaging findings, but the pleural effusion was serous. Active air leakage continued for 4 days after chest drainage, thus we decided to surgically control the air leakage and performed video-assisted surgery. A thoracoscopic examination revealed a large number of nodule parietal pleural and epiphrenic pleural nodule lesions. A pathological examination of frozen sections of the nodules indicated malignant pleural mesothelioma (MPM). Continuous air leakage was observed from the pleural surface of the right lower lobe. The air leak developed from the visceral pleura and the point of visceral pleura had a normal macroscopic appearance. The patient was treated with wedge lung resection and pleurodesis.