[A case of primary mediastinal seminoma]

Primary mediastinal seminoma is a rare clinical entity. Because of its high malignancy, we often find it only when it grows very large so we can't resect it completely. Our patient came with asthma attack and abnormal shadow on chest X-ray was pointed out. Germinal cell tumor was diagnosed by thoracoscopy and resection of the tumor was performed. Postoperative radiation therapy also was performed. Our case is alive in good health for 1 year postoperatively and good prognosis will be expected.