RCC with Xp11.2 translocation is a unique renal neoplasm more commonly found in younger patients characterized by a translocation of TFE3 gene located on chromosome Xp11.2.  This results in over-expression of the transcription factor, which can be visualized by IHC staining with Xp11.2.

 

Morphologically, these tumors are characterized by papillary architecture and clear cytoplasm.  The tumor cells appear more “pleomorphic” or “bizarre” compared to the traditional clear cell RCC.