Spontaneous Regression of Primary Pulmonary Synovial Sarcoma.

We report a rare case of primary pulmonary synovial sarcoma that underwent spontaneous regression after a transbronchial biopsy. A 38-year-old woman with a well-demarcated solitary mass shadow on chest roentgenogram was referred to us. A transbronchial biopsy was performed, and immunohistochemical results as well as detection of SYT-SSX1 (SYnovial sarcoma Translocation-Synovial Sarcoma X chromosome breakpoint) transcripts resulted in a diagnosis of synovial sarcoma. A right lower lobectomy was performed during video-assisted thoracoscopic surgery. Pathologic examination revealed widespread coagulative necrosis with feeding arterioles occluded by organized thrombi. To our knowledge, this is the first report of a case of spontaneous regression of primary pulmonary synovial sarcoma.