Review of renal carcinoma with t(6;11)(p21;q12) with focus on clinical and pathobiological aspects.

Recently, a new category of MiTF/TFE family translocation carcinomas of the kidney has been proposed. This category includes Xp11.2 renal cell carcinoma (RCC) and the t(6;11) RCC. These tumors share clinical, morphological, immunohistochemical and molecular genetic features. In this article, we review t(6;11) RCC. This tumor predominantly affects children and young adults. Macroscopically, the tumor generally forms a well circumscribed mass. Satellite nodules may be observed. Histologically, the tumor comprises large cells and small cells surrounded by basement membrane material. Immunohistochemically, tumor cells show nuclear immunolabeling for TFEB and usually express Cathepsin-K in the cytoplasm. Karyotyping detects the rearrangement between chromosome 6p21 and chromosome 11q12. Alpha-TFEB fusion can be detected by reverse transcriptase polymerase chain reaction (RT-PCR) or fluorescence in situ hybridization (FISH). Most cases affecting children and young adults seem to be indolent, but some adult cases have presented with metastasis or caused death. As previously reported cases remain limited to date, further examination in a large scale study will be needed in order to elucidate clinical behavior and molecular characteristics.