Primary anterior mediastinum undifferentiated high grade pleomorphic sarcoma is rare that most physician including thoracic surgeon would not experience this disease. Huge anterior mediastinum tumor pressed the heart and it invaded into the left pulmonary arterial trunk. We did the mediastinum tumor resection, left pneumonectomy and left phrenic, sympathetic and vagus nerve merger excision. But the recurrence lesions were detected in the right lung, the left thoracic cavity and thoracic vertebrae within one month after operation. We reported a case of aggressively progressed undifferentiated high grade pleomorphic sarcoma originated from the anterior mediastinum.
Keywords: Anterior mediastinal tumor; undifferentiated high grade pleomorphic sarcoma.