Large primary pleural synovial sarcoma with severe dyspnea: a case report

BACKGROUND: Synovial sarcoma is a malignant neoplasm of soft tissues. It occurs mainly in the extremities and is closely related to tendons, tendon sheaths, and bursal structures. Primary synovial sarcoma of the pleura and lungs is extremely rare. CASE PRESENTATION: We present the case of a 62-year-old man with a large synovial sarcoma of the left pleura. He presented with general fatigue and severe dyspnea. Chest computed tomography (CT) revealed a 20-cm tumor in the left thoracic cavity. We first diagnosed the tumor as a sarcomatoid mesothelioma based on CT-guided needle biopsy. We speculated that his severe dyspnea was because of ventilation-perfusion mismatch due to the left pulmonary collapse. Furthermore, we thought that there was a discrepancy between the CT findings and the pathological findings from the biopsy specimen. We performed pleuropneumonectomy through an anterior approach with median sternotomy and 5th-intercostal thoracotomy. The resected specimen contained a 22-cm pleural tumor with parenchymatous hemorrhage. We diagnosed the tumor as monophasic synovial sarcoma based on its morphologic and immunohistochemical features. We suspected there was microscopic residual tumor in the left diaphragm and therefore performed radiation therapy. After radiotherapy, he received adjuvant chemotherapy with ifosfamide and Adriamycin. One year after surgery, the patient is alive with no signs of tumor recurrence. CONCLUSIONS: We report a case of a large synovial sarcoma of the pleura in a patient with severe dyspnea. He was treated with pleuropneumonectomy, radiotherapy, and adjuvant chemotherapy. Although the best treatment for this rare condition has not been defined, we thought that tumor resection and adjuvant therapy were appropriate to control the disease in this case.