Int J Gynecol Pathol. 2023 Mar 1;42(2):182-191. doi: 10.1097/PGP.0000000000000868. Epub 2022 May 20.
Ovarian combined serous borderline tumor/low-grade serous carcinomas (SBT/LGSC) and mesonephric-like adenocarcinomas (MLA) have been previously reported and the presence of identical oncogenic somatic mutations in both components supports the concept that at least some of MLAs arise from a Müllerian origin. We report 2 cases of ovarian combined SBT/LGSC and mesonephric-like lesion. Case 1 was a 70-yr-old woman presented with a liver lesion and omental carcinomatosis. Histologic examination revealed biphasic tumors in bilateral ovaries consisting of conventional SBT and invasive MLA with extraovarian spread. The right ovary also had a component of cribriform variant of SBT/noninvasive LGSC. The SBT/LGSC component was diffusely positive for Pax8, WT-1, and ER, focally positive for PR, and negative for GATA3, while the MLA component was diffusely positive for GATA3 but negative for WT-1, ER, and PR. Molecular analysis revealed a KRAS G12V mutation in both the SBT/LGSC and MLA components, indicating their clonal origin. Case 2 was a 58-yr-old woman who presented with conventional type SBT in both ovaries. In addition, the left ovarian tumor demonstrated a few areas (each <5 mm) of mesonephric-like differentiation/hyperplasia in close proximity to the serous-type epithelium, with an immunophenotype of focal GATA3 expression, luminal pattern of CD10 staining and negative WT-1, ER, and PR staining. This phenomenon has been reported in endometrioid borderline tumor but not in any serous type lesions. The findings in case 1 provide further evidence to demonstrate the clonal relationship between these morphologically and immunophenotypically distinct components. It also supports the theory that, unlike cervical mesonephric carcinomas originating from mesonephric remnants, MLAs are derived from a Müllerian-type lesion with differentiation into mesonephric lineage. The presence of a hyperplastic mesonephric-like lesion/differentiation in case 2 indicates that a precursor lesion in the same lineage with the potential to develop into MLA exists in the ovary.
卵巢交界性浆液性肿瘤/低级别浆液性癌（SBT/LGSC）和中肾样腺癌（MLA）以前已有报道，两种成分中存在相同的致瘤体细胞突变，支持至少部分 MLA 起源于 Müllerian 来源的概念。我们报告了 2 例卵巢交界性 SBT/LGSC 和中肾样病变。病例 1 为 70 岁女性，因肝病变和网膜癌转移就诊。组织学检查显示双侧卵巢的双相肿瘤，由常规 SBT 和侵袭性 MLA 组成，伴有卵巢外播散。右侧卵巢还存在 SBT/非浸润性 LGSC 的筛状变异型成分。SBT/LGSC 成分弥漫性表达 Pax8、WT-1 和 ER，局灶性表达 PR，GATA3 阴性，而 MLA 成分弥漫性表达 GATA3，但 WT-1、ER 和 PR 阴性。分子分析显示 SBT/LGSC 和 MLA 成分均存在 KRAS G12V 突变，表明其克隆起源。病例 2 为 58 岁女性，双侧卵巢均为常规型 SBT。此外，左卵巢肿瘤在靠近浆液型上皮的部位有几个（每个 <5mm）中肾样分化/增生区域，免疫表型为局灶性 GATA3 表达、CD10 染色的腔隙模式和 WT-1、ER 和 PR 染色阴性。这种现象已在子宫内膜样交界性肿瘤中报道，但不在任何浆液型病变中报道。病例 1 的发现进一步证明了这些形态和免疫表型明显不同的成分之间的克隆关系。它还支持这样的理论，即与起源于中肾残余的宫颈中肾样癌不同，MLA 源自 Müllerian 样病变，并分化为中肾谱系。病例 2 中存在增生性中肾样病变/分化表明，卵巢中存在具有发展成 MLA 潜力的同系前病变。
