Translocation Renal Cell Carcinomas in Adults

Translocation renal cell carcinoma is a newly recognized subtype of renal cell carcinoma (RCC) with chromosomal translocations involving TFE3(Xp11.2) or, less frequently, TFEB(6p21). Xp11 translocation RCC was originally described as a pediatric neoplasm representing 20 to 40 of pediatric RCCs, with a much lower frequency in the adult population. TFEBtranslocation RCC is very rare, with approximately 10 cases reported in the literature. Here, we describe the clinicopathologic features of adult translocation RCC from a single institution. Using tissue microarray, immunohistochemistry, cytogenetic examination, and fluorescence in situ hybridization, we identified 6 (∼5) cases of TFE3translocation RCC and 1 (<1) case of TFEBtranslocation RCC in 121 consecutive adult RCC cases between 2001 and 2009. Our results suggest that weak TFE3 staining of a significant proportion of RCC cases may be because of expression of the full-length TFE3 protein rather than the chimeric fusion protein resulting from chromosomal translocation.