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

Sex Cord-Stromal Tumors of the Ovary: An Update and Review. Part I - Pure Ovarian Stromal Tumors

In two separate reviews, we review the time-honored but still frequently challenging features of ovarian sex cord-stromal tumors, and also emphasize new developments including unusual morphologic appearances that, despite the relative rarity of many of the tumors, result in a disproportionate number of differential diagnostic problems, variant immunohistochemical profiles, and specific molecular and syndromic associations. These neoplasms are also of historical interest as current knowledge is still based in significant part on the contributions of 2 giants of gynecologic pathology, Dr Robert Meyer and Dr Robert E. Scully. In part I, we present the major clinical, pathologic, and genomic features of the pure ovarian stromal tumors including comments on differential diagnosis and briefly note significant historical contributions. In part II we will discuss pure sex cord and sex cord-stromal tumors.

Histological and immunohistochemical characterization of 17 gonadal tumours in koi carp (Cyprinus carpio koi)

Reports on abdominal tumours in koi carp are scarce and most are from the gonads. Their histological diagnosis is challenging due to the occurrence of mixed populations of neoplastic cells and the few availability of cross-reactive antibodies in fish tissues. The present study aims to provide a histopathological characterization of seventeen gonadal tumours, enriched by a wide antibody panel (vimentin, CD117, placental alkaline phosphatase-PLAP, AE1/AE3 cytokeratin, E-cadherin, proliferating cell nuclear antigen-PCNA, müllerian-inhibiting substance-MIS, GATA4 and Inhibin-α) applied on whole and tissue microarray (TMA) sections. Abdominal enlargement was associated with tumours filling 30%-80% of the abdominal cavity; frequently, the gonads had been completely replaced by neoplastic tissue. Twelve cases were characterized as sex cord-stromal tumours (SCSTs), three as germ cell tumours (GCTs), one as mixed germ cell sex cord-stromal tumour (MGCSCST) and one as carcinoma. By immunohistochemistry, PLAP enabled confirmation of GCTs, ovarian carcinoma and the objective identification of a further cell component in 8 out of the 12 SCSTs that were reclassified as mixed tumours. The use of an immunohistochemical panel can help in refining the histological diagnosis, but the morphological diagnosis still represents the main tool for the characterization of these tumours in koi carp.

The role of FOXL2, SOX9, and β-catenin expression and DICER1 mutation in differentiating sex cord tumor with annular tubules from other sex cord tumors of the ovary

Sex cord tumor with annular tubules (SCTAT) is a highly rare type of ovarian sex cord-stromal tumor (SCST), the diagnosis of which remains to be challenging. The aim of this study was to scrutinize the utility of three immunohistochemical markers including Forkhead box protein 2 (FOXL2), SOX9, and β-catenin and DICER1 mutation status in distinguishing SCTATs from other ovarian SCSTs. Nine cases of SCTAT, 10 Sertoli-Leydig cell tumor (SCLT), 10 adult-type granulosa cell tumor (AGCT), and 8 juvenile-type granulosa cell tumor (JGCT) were included in the study. SCTATs were characterized by diffuse and strong expression of SOX9, focal and weak expression of FOXL2, and the absence of DICER1 mutation. However, AGCTs and JGCTs displayed strong and diffuse expression of FOXL2, focal/no immunoreaction for SOX9. SLCTs generally showed moderate intensity of FOXL2 and SOX9 expression. Nuclear β-catenin expression was observed in none of SLCT, 1/9 of SCTAT, 6/8 JGCT, and 4/10 AGCT cases, respectively. DICER1 hotspot mutation was detected in only 3 cases of SLCT and 2 cases of JGCT. We conclude that in addition to strong and diffuse SOX9 expression, weak/absent expression of FOXL2 is suggestive for the diagnosis of SCTAT. Hence, we suggest that inclusion of these two markers, SOX-9 and FOXL2, to the immunohistochemical panel helps in differentiation of SCTAT from other SCSTs in addition to morphologic findings. We also conclude that SCTATs of the ovary do not harbor DICER1 hotspot mutation.

Practical roles for molecular diagnostic testing in ovarian adult granulosa cell tumour, Sertoli-Leydig cell tumour, microcystic stromal tumour and their mimics

Within the last decade, molecular advances have provided insights into the genetics of several ovarian sex cord-stromal tumours that have otherwise been enigmatic. Chief among these advances are the identification of FOXL2, DICER1 and CTNNB1 mutations in adult granulosa cell tumours, Sertoli-Leydig cell tumours (SLCTs), and microcystic stromal tumours (MCSTs), respectively. As access to molecular diagnostic laboratories continues to become more widely available, the potential roles for tumour mutation testing in the pathological diagnosis of these tumours merit discussion. Furthermore, links to inherited cancer susceptibility syndromes may exist for some women with SLCT (DICER1 syndrome) and MCST [familial adenomatous polyposis (FAP)]. This review will address practical issues in deciding when and how to apply mutation testing in the diagnosis of these three sex cord-stromal tumours. The pathologist's role in recommending referral for formal risk assessment for DICER1 syndrome and FAP will also be discussed.