Abstract
Primary renal synovial sarcoma (PRSS) is an exceedingly rare malignancy. Due to its rarity, the diagnosis and management of PRSS remain challenging, as there are no standardized treatment guidelines. We present a case of a 35-year-old male who presented with right flank pain for two months. Contrast-enhanced CT (CECT) revealed a 10 × 11 × 12 cm mass at the upper pole of the right kidney. The patient underwent radical nephrectomy, and histopathological examination suggested synovial sarcoma. To confirm the diagnosis, we performed a translocation study, which identified the SS18 gene translocation at 18q11, a hallmark of synovial sarcoma. Postoperatively, the patient received adjuvant chemotherapy with the AIM (doxorubicin, ifosfamide, and mesna) regimen. Given the extreme rarity of PRSS, we discuss the diagnostic challenges, molecular characteristics, and treatment approach adopted at our institution, contributing to the limited but growing body of knowledge on this rare entity.