[Diagnostic value of immunohistochemistry in ovarian sex cord-stromal tumors]

The ovarian tumors' diagnosis is based on biological and radiologic tests but only the histological examination associated to an immunohistochemical study allow best diagnosis.The purposes of this study is to examine inhibin and other markers immunoreactivity to ovarian sex cord-stromal tumors and their histological mimics and to discuss its value in the differential diagnosis.We report a retrospective study of 31 cases of ovarian sex cord-stromal tumors and review the clinical, pathologic and immunohistochimical features of these tumors.The average age of our patients was 51,3 years with an average size of 8,4cm. Immunostaining for inhibin was positive in 66% of granulosa cell tumor, in 50% of Sertoli-Leydig cell tumor and in 54% of thecoma-fibroma group. Inhibin immunoreactivity was more important than with cytokeratin and epithelial membrane antigen, but less marked than with CD99, vimentin, smooth muscle actin, desmin and S-100 protein.The results of this study show that although it is not complete specificity, inhibin, contrarily to the other markers, can be used to help in the distinction between ovarian sex cord-stromal neoplasms and the other primary and metastatic tumors.