Sukov William R, Cheville John C, Lager Donna J, Lewin Jock R, Sebo Thomas J, Lewin Matthew
Mayo Clinic, Pathology, Rochester, MN 55905, USA.
Hum Pathol. 2007 Sep;38(9):1432-7. doi: 10.1016/j.humpath.2007.03.022.
Mixed epithelial stromal tumor of the kidney (MEST)/adult cystic nephroma (CN) is a lesion characterized by epithelial lined tubular or cystic structures interspersed within a variably prominent, distinctive spindle-cell stroma. Although typically benign, cases with malignant features have been reported. Herein, we report a MEST/CN with malignant stromal features and rhabdoid differentiation arising in the left kidney of an 84-year-old woman. Histologically, the tumor displayed multiple tubules and variably sized cystic structures lined by benign epithelium with an intervening malignant-appearing spindle-cell stroma. The malignant stroma displayed condensation in the regions surrounding the epithelial component consistent with the ovarian-like stroma typically observed in MEST/CN. In addition, the stromal cells displayed extensive rhabdoid differentiation. Immunohistochemical analysis revealed strong expression of cytokeratin 7, CAM 5.2, AE1/AE3, wide-spectrum keratin, and epithelial membrane antigen by the epithelial component. The stromal component displayed strong immunohistochemical expression of WT-1, CD-99, CD-56, INI1, and estrogen receptor; focal actin positivity; and was negative for desmin, myogenin, and progesterone receptor. Analysis by reverse transcriptase polymerase chain reaction failed to identify the SYT-SSX1 or SYT-SSX2 fusion transcripts characteristic of synovial sarcoma. To our knowledge, this represents the first report in the literature of malignant MEST with rhabdoid features and suggests that this entity should be considered in the diagnosis of renal stromal malignancies with prominent rhabdoid features.
肾混合性上皮间质瘤（MEST）/成人囊性肾瘤（CN）是一种病变，其特征为上皮内衬的管状或囊性结构散布于不同程度突出的、独特的梭形细胞间质中。尽管通常为良性，但已有报道出现具有恶性特征的病例。在此，我们报告一例发生于一名84岁女性左肾的具有恶性间质特征和横纹肌样分化的MEST/CN。组织学上，肿瘤显示多个小管和大小不一的囊性结构，内衬良性上皮，其间为外观呈恶性的梭形细胞间质。恶性间质在围绕上皮成分的区域出现凝聚，与MEST/CN中通常观察到的卵巢样间质一致。此外，间质细胞显示广泛的横纹肌样分化。免疫组织化学分析显示上皮成分强烈表达细胞角蛋白7、CAM 5.2、AE1/AE3、广谱角蛋白和上皮膜抗原。间质成分免疫组织化学强烈表达WT-1、CD-99、CD-56、INI1和雌激素受体；局灶性肌动蛋白阳性；结蛋白、肌细胞生成素和孕激素受体阴性。逆转录聚合酶链反应分析未能鉴定出滑膜肉瘤特有的SYT-SSX1或SYT-SSX2融合转录本。据我们所知；这是文献中首例具有横纹肌样特征的恶性MEST报告；提示在诊断具有显著横纹肌样特征的肾间质恶性肿瘤时应考虑这一实体。
