[Mediastinal Dedifferentiated Liposarcoma Resected with Partial Resection of Pericardium].

An anterior mediastinal tumor was detected by computed tomography (CT) in a 66-year-old man who complained of left flank pain, and the surgical treatment was performed. At surgery, partial resection of the pericardium was also conducted because the pericardial inversion was suspected. The histopathological diagnosis was dedifferentiated liposarcoma. The patient is well without adjuvant chemotherapy 23 months after the surgery.