子宫内膜或卵巢的中肾样腺癌 (MLA) 是一种罕见但独特的子宫内膜癌，具有特征性形态学、免疫组织化学 (IHC) 和分子特征。 SOX17 最近被确定为子宫内膜癌和卵巢癌的高度敏感和特异性标记物。在本研究中，我们旨在与其他 IHC 一起研究 MLA 中 SOX17 的表达，以将 MLA 与其他子宫内膜癌区分开来。收集了 17 个既往诊断的子宫内膜/卵巢 MLA，并进行了多次 IHC。此外，我们对2012年至2015年MLA诊断标准尚未建立的652例子宫内膜癌组成的组织微阵列（TMA）进行了SOX17、PAX8和ER检测。所有17个MLA均显示弥漫性强阳性PAX8、阴性ER和可变TTF1/GATA3染色。值得注意的是，所有 MLA 均显示 SOX17 阴性 (n = 10) 或局灶性弱/中度 (n = 7) 染色，SOX17 比其他子宫内膜癌亚型中的 PAX8 更弥散且更强。这一发现促使我们通过 SOX17 和 PAX8 IHC 联合的方法对 MLA 前诊断的 652 例子宫内膜癌进行 TMA 筛查，并鉴定出 14 例 PAX8 阳性但 SOX17 阴性/局灶性弱的病例。我们通过检查形态学和进行额外的 IHC（TTF1、GATA3、ER 和 CD10）进一步研究了 14 例病例，并根据形态学特征和阳性 CD10、TTF1 和/或 GATA3 染色将其中 7 例 (50%) 分类为 MLA。结果表明，如果结果显示 PAX8 强阳性，但 SOX17 阴性，则 SOX17 和 PAX8 IHC 的组合将有助于诊断 MLA。© 2024 作者。组织病理学由约翰·威利出版

Mesonephric-like adenocarcinoma (MLA) of the endometrium or ovary is a rare but distinct endometrial carcinoma which has a combination of characteristic morphological, immunohistochemical (IHC) and molecular features. SOX17 has been recently identified as a highly sensitive and specific marker for endometrial and ovarian carcinomas. In this study, we aimed to investigate SOX17 expression in MLA together with other IHCs to differentiate MLAs from other endometrial carcinomas.Seventeen previously diagnosed endometrial/ovarian MLAs were collected, and multiple IHCs were performed. Additionally, we performed SOX17, PAX8 and ER on tissue microarrays (TMAs) composed of 652 endometrial carcinomas from 2012 to 2015 when MLA diagnostic criteria were not established.All 17 MLAs showed diffuse strong positive PAX8, negative ER and variable TTF1/GATA3 staining. Notably, all MLAs showed negative (n = 10) or focal weak/moderate (n = 7) staining for SOX17, which is more diffuse and stronger than PAX8 in other endometrial carcinoma subtypes. This finding prompted us to screen TMAs with 652 endometrial carcinomas diagnosed before MLA by an approach of combined SOX17 and PAX8 IHCs, and 14 cases with positive PAX8 but negative/focal weak SOX17 were identified. We further studied the 14 cases by examining morphology and performing additional IHCs (TTF1, GATA3, ER and CD10) and would classify seven (50%) of them as MLAs based on morphological features and positive CD10, TTF1 and/or GATA3 staining.Our results suggest that a combination of SOX17 and PAX8 IHCs would aid in diagnosing MLA if the results show strong positive PAX8, but negative SOX17.© 2024 The Author(s). Histopathology published by John Wiley & Sons Ltd.