Translocation carcinomas of the kidney.

A significant proportion of RCCs of children and young adults bear specific chromosome translocations that result in gene fusions that involve members of the MiTF/TFE transcription factor family. These include the Xp11-translocation carcinomas, which bear TFE3 gene fusions, and the renal carcinomas with the t(6;11)(p21;q12), which bear an Alpha-TFEB gene fusion. Both types of translocation result in overexpression of the fusion gene products, such that nuclear labeling for TFE3 or TFEB by immunohistochemistry is a sensitive and specific marker of these respective tumor types. The clinical behavior of these neoplasms relative to conventional, adult-type renal carcinomas remains to be determined, and will be an important area of future investigation.