Uterine tumors resembling ovarian sex cord tumors (UTROSCT) lack the JAZF1-JJAZ1 translocation frequently seen in endometrial stromal tumors.

Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare uterine neoplasm composed predominantly or exclusively of cells which resemble those seen in sex cord tumors of the ovary. Since its initial morphologic description, it has been unclear whether UTROSCT represents a variant within the spectrum of endometrial stromal tumors (ESTs), which may rarely exhibit areas of sex cord-like differentiation, or whether it is a distinct uterine neoplasm unrelated to ESTs. Recently, several studies have revealed a recurrent t(7;17) translocation resulting in a JAZF1-JJAZ1 gene fusion in over 60% of EST and its variants, including 2 out of 4 endometrial stromal tumors with sex cord-like elements (ESTSCLE). We examined UTROSCTs for evidence of the JAZF1-JJAZ1 gene fusion by fluorescence in situ hybridization and by reverse transcriptase polymerase chain reaction in 24 and 20 cases, respectively. The JAZF1-JJAZ1 gene fusion was not identified in any tumor by either method. Although we cannot entirely exclude that UTROSCT represents a variant of ESTSCLE which lacks this translocation, our findings suggest that UTROSCT does not share the genetic mechanism common to the majority of ESTs with or without sex cord-like differentiation, and therefore most likely represents a distinct neoplasm unrelated to ESTSCLE.