Eight years ago, A 29-year-old woman was admitted by complaining with facial edema and dyspnea. A chest x-ray film and computed tomography showed an anterior mediastinal tumor that invaded to the superior vena cava and the trachea. A bronchoscopic biopsy revealed that the tumor was a thymoma. We performed radiotherapy and chemotherapy because a surgical operation was not possible. The size of the tumor was slightly reduced after those therapies roentgenographically. We followed up the subsequent of history of the patient. Eight years later, July, 1995, chest computed tomography showed bilateral disseminations of invasive thymoma. The disseminated tumors were removed by two-stage video assisted thoracoscopic surgery (VATS), to preserve collateral veins so that collateral venous circulations were preserved. She discharged 20 days after second VATS uneventfully.