Differential expression of E-cadherin and catenins in ovarian sex cord stromal tumours

Aims: Sex cord stromal tumours (SCSTs) of the ovary encompass several histological tumour subtypes that are defined by characteristic histological features. Some can show morphological overlap with other subtypes of SCSTs, as well as with non-SCSTs. The E-cadherin/catenin complex constitutes the adherens junction, which is well developed in epithelial tissue, but the constituent molecules are also expressed in several non-epithelial tumours. The aim of this study was to determine whether the expression patterns of E-cadherin and catenins in ovarian SCSTs can be of diagnostic utility. Methods and results: We studied the expression of E-cadherin, α-, β- and γ-catenin in 55 tumours using immunohistochemistry. We found that all tumour subtypes showed nuclear expression of E-cadherin, while only microcystic stromal tumours (MCSTs) displayed a distinct profile, with nuclear localization of all three catenins in almost all cases. Conclusions: We conclude that the E-cadherin expression profile in SCSTs can assist in distinguishing between SCSTs and non-SCSTs in which there is no nuclear expression of E-cadherin. The nuclear localization of catenins may be of potential use in distinguishing MCST from other subtypes of SCST.