Primary renal synovial sarcoma: two cases and review of the literature

Objective: To investigate the clinicopathological features, treatment, and prognosis of primary renal synovial sarcoma. Method: Retrospectively collected and analyzed clinical and pathological data of two cases of patients with renal primary synovial sarcoma, and reviewed domestic and foreign related literature. Results: The first patient was admitted for progressive enlargement of a left renal mass, then she underwent a radical resection of left kidney and adrenal gland, and the final diagnosis was primary renal synovial sarcoma. However, the tumor progressed with multiple nodules in the left peritoneal retroperitoneal space and abdominal wall 3 months later. The second patient was hospitalized for a left lung mass and left renal mass after 3 months. She received left nephrectomy and left lower lobectomy. The final diagnosis was primary renal synovial sarcoma with extensive metastasis in both lungs and pelvic and abdominal cavity. The patient underwent chemotherapy and targeted therapy after operation, and died because of tumor burden after 23 months. Conclusion: Primary renal synovial sarcoma is a rare soft tissue tumor in the kidney with a poor prognosis. An accurate diagnosis needs consideration of the morphology, immunohistochemistry, and SYT-SSX gene results. Clinically, radical nephrectomy is the main strategy, and adjuvant ifosfamide-based chemotherapy after operation has benefits.