[Pulmonary Carcinosarcoma Presenting Hemothorax Caused by Pleural Invasion;Report of a Case].

: A 71-year-old man presented with hemothorax with cough, sputa and worsening dyspnea. On chest X-ray and computed tomography(CT), a huge tumor in the right upper lobe with hematoma and small amount of gas suggesting hemopneumothorax was revealed. No apparent lymphadenopathy nor intrapulmonary metastases were observed. The tumor showed a little enhancement on the contrastenhanced CT. Then the resction of the tumor was performed, and the pathological evaluation revealed a carcionosarcoma (adenocarcinoma+osteosarcoma) pT3N0 (stage II B) G4 pl2. Sarcomatoid carcinoma such as carcinosarcoma should be considered as a possible cause of hemothorax in making a diagnosis of hemorrhagic hypovascular huge lung tumor.