[A surgical case for the huge chronic expanding hematoma developed in the thoracic cavity].

We report a case of operation against chronic expanding hematoma developed in the pleural cavity of the patient who were treated as anaplastic anemia. 69-year-old man had been underwent thymectomy because of the thymoma and hemogenic pleural effusion 8 years ago. Then, last year, he was pointed out severe thrombocytopenia and underwent transfusion of thrombocyte. In the same period, chest X-ray examination revealed development of the tumor-like shadow in the left lung field. The abnormal shadow has enlarged, so the patient admitted us. X-ray findings revealed the huge tumor occupied completely the left pleural space. He was also pointed out severe pancytopenia (WBC: 2,600/mm3, RBC: 172 x 10(4)/mm3, thrombocyto: 1.9 x 10(4)/mm#), and the examination of bone marrow revealed anaplastic anemia. Thoracotomy was underwent, and the tumor was resected. Pathological diagnosis of the tumor was huge hematoma. Negative pressure in the pleural space would keep the hemorrhage and make hematoma huge. The hematoma in the pleural space should be resected as soon as the diagnosis is decided.