[A case of malignant mesothelioma presenting with recurrent pneumothorax].

A 71-year-old man was found to have right hydropneumothorax by chest X-ray film on a regular checkup. Thoracic drainage and bullectomy by thoracoscopy did not improve the pneumothorax, so pleurodesis with OK-432 was done. Pneumothorax recurred twice, requiring thoracic drainage and pleurodesis. Although pneumothorax was treated successfully, increased pleural effusion, pleural thickening and subcutaneal tumor at the thoracic drainage suture site developed. The concentration of hyaluronic acid in the pleural fluid was very high. The histological examination of the biopsied subcutaneous tumor showed mixed type malignant pleural mesothelioma. Chemotherapy with gemcitabine and vinorelbine could not control the progression.