[Primary pulmonary synovial sarcoma confirmed by gene expression analysis].

We report a patient who was diagnosed with synovial sarcoma based on gene expression analysis. A 39-year-old male visited a local hospital due to left chest pain. Chest compued tomography (CT) showed a lung tumor located mainly at the lingula of the left lung, and extending to the bifurcation of the upper and lower lobar bronchi. Left pneumonectomy was performed. Pathological examination showed a mesenchymal tumor consisting of short-spindle, small, round cells, and the differentiation between synovial sarcoma and peripheral neuroectodermal tumor was necessary. RT-PCR to examine the gene expression of cells revealed a SYT-SSX fusion gene, and a diagnosis of primary synovial sarcoma of the lung was made.