Persistent complete response after single-agent sunitinib treatment in a case of TFE translocation positive relapsed metastatic pediatric renal cell carcinoma.

Forty percent of renal cell carcinomas (RCCs) in childhood are characterized by translocation involving transcription factor E3 (TFE3) family members. Here, we describe a case of TFE3-positive RCC in which metastatic relapse to the mediastinal lymph nodes and pulmonary nodules was treated with single-agent sunitinib, a multitargeted tyrosine inhibitor. Complete radiologic remission was achieved after only 3 courses of treatment, and surgical exploration of metastases failed to identify any residual viable disease. The published experience of sunitinib in TFE-RCC is limited, and prospective evaluation of its activity in a larger number of patients is warranted.