A case of synovial sarcoma of the mediastinum]

A 65-year-old man consulted our hospital with a complaint of bloody sputum in February 2006, and chest computed tomography (CT) showed a mediastinal tumor. Percutaneous needle biopsy was performed. Pathological examination of the specimen revealed spindle-shaped cells; on immunohistochemical testing the tumor cells were positive for vimentin, keratin, EMA, CD99, actin, alpha-SMA, CD56, NF, and S100, and amplication of the SYT-SSX fusion gene was also seen. Thus, we confirmed a diagnosis of synovial sarcoma. The patient received chemotherapy, radiation therapy and hyperthermia therapy, but the tumor progressed and he died in October 2007. Synovial sarcoma commonly occurs in the vicinity of the large joints. We report an important case of mediastinal synovial sarcoma, which is comparatively rare.