Revista de citología e histología

Renal Cell Carcinoma Associated with Xp11.2 Translocation/Transcription Factor E3 (TFE3) Fusion

Abstract

Borislav A. Alexiev

Renal cell carcinomas (RCC) associated with Xp11.2 translocations (Xp11.2 TRCCs) form a new and little known entity of the WHO 2004 classification [1-23]. de Jong et al. [1] and Tomlinson et al [2] first described Xp11 translocation as a previously unknown finding in the karyotype of two atypical renal masses presenting in infant males [13]. These neoplasms are defined by several translocations involving the transcription factor 3 (TFE3) gene that is located on chromosome Xp11.2, resulting in a gene fusion between TFE3 and at least 5 possible partners [3-7,16,18,21,23]. These include a distinctive RCC which bears a translocation with the identical chromosomal breakpoints (Xp11.2, 17q25) and identical resulting ASPL-TFE3 gene fusion as alveolar soft part sarcoma (ASPS), with the distinction that the t(X;17) translocation is cytogenetically balanced in these renal tumors [4]. The most commonly observed translocations are t(X;17)(p11.2;q25), t(X;1) (p11.2;p34), and t(X;1)(p11.2;q21), which lead to gene fusions of TFE3 with ASPL, PSF, and PRCC, respectively [3,15,16]. This review aims to highlight the helpful histologic, immunohistochemical, and cytogenetic features of this entity to enable correct diagnosis.