Multidrug refractory aggressive metastatic TFE3 (+) renal cell carcinoma: A case report.

Background: Transcription factor E3 (TFE3) related renal cell carcinomas constitute a very small percent of all renal tumors in adults. Prognosis mainly depends on the stage of the disease at the time of diagnosis which is often poor. There is yet to be a standardized treatment protocol. Treatment options include agents identical to TFE3(-) cell renal carcinoma treatment. We present a case of a young woman with a rapidly progressing metastatic TFE3 (+) renal cell carcinoma.
Case Report: A 31 year old female presented with abdominal mass, distension, nausea. Initial tests and tumor markers found to be normal. Abdominal CT scan revealed a left retroperitoneal mass along with three other neighboring masses in liver manifesting as metastases. Trucut biopsy and immunohistochemical staining confirmed the retroperitoneal mass as TFE3 (+) renal cell carcinoma. Management and outcome: Sunitinib, pazopanib, nivolumab, axitinib treatments are consecutively given after surgery. It is noteworthy that rapid progression was observed under nivolumab treatment.
Discussion: During surveillance, rapid progression is noted under consecutive immunotherapy which was unexpected. Thus, there is a need for more standardized treatment protocols and invention of new agents for management of TFE3 (+) renal cell carcinoma.