Primary renal synovial sarcomas diagnosed by a novel fusion gene with the fusion site involving exons of SS18 and SSX2: a case report

Objectives: Primary renal synovial sarcoma (PRSS) is an uncommon malignancy with diagnostic challenges and poor prognosis. Research on PRSS is limited, primarily based on case reports, leading to a lack of widely recognized effective treatment options. This article reports a case of primary renal synovial sarcoma diagnosed using a novel fusion gene with a fusion site involving the SS18 and SSX2 exons. Case presentation: A 34-year-old male, presented with intermittent right upper abdominal pain. Abdominal CT revealed an isolated mass in the upper pole of the right kidney, which was initially diagnosed as renal cell carcinoma. The patient underwent radical right nephrectomy, and postoperative histopathological examination confirmed the diagnosis of synovial sarcoma, and immunohistochemistry supported the diagnosis. Further detection through RT-PCR and DNA sequencing confirmed the presence of the SS18-SSX2 fusion gene. Despite the recommendation for adjuvant therapy, the patient refused chemotherapy and other treatments and succumbed to systemic metastasis. Conclusions: This case highlights the diagnostic challenges and aggressive nature of PRSS. The novel fusion gene with the fusion sites SS18: exon9 and SSX2: exon5 has important implications for the diagnosis of primary synovial sarcoma of the kidney. Further research is warranted to explore novel therapeutic strategies and improve patient outcomes in PRSS.