Tahir Maryam, Xing Deyin, Ding Qingqing, Wang Yihong, Singh Kamaljeet, Suarez Adrian A, Parwani Anil, Li Zaibo
Department of Pathology, The Ohio State University, Columbus, OH, USA.
Department of Pathology, The John Hopkins University, Baltimore, MD, USA.
Histopathology. 2025 Jan;86(2):268-277. doi: 10.1111/his.15312. Epub 2024 Sep 4.
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.
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，具有特征性的形态学、免疫组化（IHC）和分子特征。SOX17最近被确定为子宫内膜癌和卵巢癌的一种高度敏感和特异的标志物。在本研究中，我们旨在研究SOX17在MLA中的表达以及其他免疫组化指标，以将MLA与其他子宫内膜癌区分开来。
收集17例先前诊断的子宫内膜/卵巢MLA病例，并进行多种免疫组化检测。此外，我们对2012年至2015年期间未建立MLA诊断标准时的652例子宫内膜癌组织芯片（TMA）进行了SOX17、PAX8和雌激素受体（ER）检测。
所有17例MLA均显示弥漫性强阳性PAX8、阴性ER以及TTF1/GATA3染色情况各异。值得注意的是，所有MLA均显示SOX17染色阴性（n = 10）或局灶性弱阳性/中度阳性（n = 7），这在其他子宫内膜癌亚型中比PAX8更为弥漫和强烈。这一发现促使我们通过联合SOX17和PAX8免疫组化方法对652例在MLA诊断标准确立之前诊断的子宫内膜癌组织芯片进行筛查，共鉴定出14例PAX8阳性但SOX17阴性/局灶性弱阳性的病例。我们通过检查形态学并进行额外的免疫组化检测（TTF1、GATA3、ER和CD10）对这14例病例进行了进一步研究，基于形态学特征以及CD10、TTF1和/或GATA3染色阳性，将其中7例（50%）归类为MLA。
我们的结果表明，如果SOX17和PAX8免疫组化结果显示PAX8强阳性但SOX17阴性，联合检测将有助于诊断MLA。
