Primary Synovial Sarcoma of the Parietal Pleura: A Case Report
A 53-year-old woman was admitted to the Department of Cardiothoracic Surgery because of upper right back pain for 2 weeks. Her vital signs were within normal limits, and physical examination revealed no abnormal findings. Her laboratory findings were also within normal limits. Computed tomography of the chest demonstrated a heterogeneous mass (4.0×3.0×3.0 cm) attached to the right parietal pleura with direct invasion of the posterior arch of the right 4th rib (). Positron emission tomography demonstrated a hypermetabolic mass attached to the right parietal pleura. The maximum standardized uptake value of the mass was 8.0. There was no evidence of definite metastasis. The patient underwent surgical resection through a right posterolateral thoracotomy. Intraoperatively, there was an encapsulated soft mass in the posterior portion of the right 3rd intercostal space. There was direct invasion of the right 3rd and 4th ribs; however, there was no invasion of the right lung. A radical resection of the tumor including the right 3rd and 4th ribs was performed. The chest wall defect was repaired with a Gore-Tex Dual-Mesh patch (2 mm). On histopathological examination (), the tumor was confirmed to be a poorly differentiated monophasic synovial sarcoma. The histopathological specimen showed synovial sarcoma composed of spindle cells with a hemangiopericytoma-like vascular pattern. The tumor cells showed immunohistochemical positivity for vimentin, a sarcoma tumor marker for identifying mesenchyme; focal weak positivity for epithelial membrane antigen; but immunohistochemical negativity for S-100 protein, CD34 and actin, the other fibrous tumor markers. The patient was discharged in stable condition 5 weeks after the operation and she received adjuvant radiotherapy at another hospital.