Adley Brian P, Papavero Veronica, Sugimura Jun, Teh Bin T, Yang Ximing J
Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA.
Anal Quant Cytol Histol. 2006 Aug;28(4):228-36.
To investigate the diagnostic value of cytokeratin 7 (CK7) and parvalbumin at mRNA and protein levels.
CK7 and parvalbumin mRNA expression levels in 23 oncocytomas and 32 chromophobe renal cell carcinomas (RCCs) were examined using gene expression microarrays. Immunohistochemistry was performed using monoclonal antibodies specific for CK7 or parvalbumin in 41 chromophobe RCCs and 55 oncocytomas.
CK7 mRNA was overexpressed in 18 of 32 chromophobe RCCs but only 3 of 23 oncocytomas. Parvalbumin mRNA was overexpressed in 15 of 32 chromophobe RCCs and only 4 of 23 oncocytomas. In contrast, CK7 mRNA underexpression was noted in 13 of 23 oncocytomas and only 6 of 32 chromophobe RCCs, while parvalbumin underexpression was seen in 14 of 23 oncocytomas but only 6 of 32 chromophobe RCCs. By immunohistochemistry, 27 of 41 (66%) chromophobe RCCs expressed CK7 diffusely compared to only 3 of 55 (5%) oncocytomas. Diffuse parvalbumin expression was seen in all 41 of 41 (100%) chromophobe RCCs and only in 26 of 55 (47%) oncocytomas.
Both mRNA and protein expression levels of CK7 appear significantly higher in chromophobe RCC compared to oncocytoma (p < 0.001). Parvalbumin expression is less specific but often displays a patchy pattern in oncocytomas. Our study provides further evidence that CK7 and parvalbumin immunostains may be useful in differentiating oncocytoma from chromophobe RCC in problematic cases. Negative or patchy staining (< 50% cells) for CK7 and/or parvalbumin strongly favors the diagnosis of oncocytoma.
研究细胞角蛋白7（CK7）和小白蛋白在mRNA和蛋白质水平的诊断价值。
使用基因表达微阵列检测23例嗜酸细胞瘤和32例嫌色肾细胞癌（RCC）中CK7和小白蛋白的mRNA表达水平。在41例嫌色RCC和55例嗜酸细胞瘤中，使用针对CK7或小白蛋白的单克隆抗体进行免疫组织化学检测。
在32例嫌色RCC中的18例中CK7 mRNA过表达，但在23例嗜酸细胞瘤中仅3例。在32例嫌色RCC中的15例中小白蛋白mRNA过表达，在23例嗜酸细胞瘤中仅4例。相反，在23例嗜酸细胞瘤中的13例中观察到CK7 mRNA低表达，在32例嫌色RCC中仅6例，而在23例嗜酸细胞瘤中的14例中观察到小白蛋白低表达，在32例嫌色RCC中仅6例。通过免疫组织化学，41例嫌色RCC中的27例（66%）弥漫性表达CK7，而55例嗜酸细胞瘤中仅3例（5%）。在所有41例（100%）嫌色RCC中均观察到弥漫性小白蛋白表达，而在55例嗜酸细胞瘤中仅26例（47%）。
与嗜酸细胞瘤相比，嫌色RCC中CK7的mRNA和蛋白质表达水平均显著更高（p < 0.001）。小白蛋白表达特异性较低，但在嗜酸细胞瘤中常呈斑片状。我们的研究提供了进一步的证据，表明在疑难病例中，CK7和小白蛋白免疫染色可能有助于嗜酸细胞瘤与嫌色RCC的鉴别诊断。CK7和/或小白蛋白呈阴性或斑片状染色（< 50%细胞）强烈支持嗜酸细胞瘤的诊断。
