Radical Nephrectomy of a Huge Renal Mass Adherent to the Liver, Diaphragm and Aorta: The Challenges in the Identification and Management of Synovial Sarcoma of the Kidney

Abstract

Synovial sarcoma (SS) is a mesenchymal tumor that more rarely affects the kidneys. As of 2020, only around 100 cases of renal SS have been reported. Herein described is a 28-year-old female with a huge mass occupying almost the entire abdomen. Her history, physical examination and imaging suggested a renal cell carcinoma with metastases to the diaphragm, liver and large vessels. A radical nephrectomy was successfully performed, removing an enormous 26-kilogram, 52cm x 37cm x 14cm right renal mass and providing immediate relief. Histopathology surprised the authors with findings of extra-gastrointestinal stromal tumor. 20 months post-surgery, there was tumor recurrence, and a metastasectomy was done. Immunostaining revealed renal synovial sarcoma. To date, the patient remains asymptomatic and disease free. The rarity of renal SS, as well as its ability to mimic more common tumors, makes clinicopathological diagnosis and management difficult. Moreover, the role of chemotherapy for SS remains unclear.