Primary synovial sarcoma of the lung.

A 45 -year-old woman presented chest pain and a well-defined oval shaped mass on a chest radiograph. A malignant pulmonary tumor was suspected and a right pneumonectomy was performed. The tumor measured about 13 x 12 cm, was pale-yellow in color and soft in texture. Histologically, it had round to oval and spindle-shaped cells with minimal cytoplasm, hyperchromatic nuclei, inconspicuous mitoses and only slight fibrous stroma. Immunohistochemically, the tumor cells were positive for vimentin, CD 99, BCL-2 protein and EMA. The reverse transcriptase-polymerase chain reaction (RT-PCR), using RNA extracted from fresh-frozen tissue, demonstrated SYT/SSX-2 fusion transcripts, confirming the diagnosis of synovial sarcoma.