Foster M R, Johnson J E, Olson S J, Allred D C
Department of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Arch Pathol Lab Med. 2001 Oct;125(10):1316-20. doi: 10.5858/2001-125-1316-IAONVC.
Previous studies have indicated certain immunohistochemical markers, including WT1, may be helpful in distinguishing adenocarcinomas from mesotheliomas, but to date there are no reliable, widely accepted, commercially available antibodies positive in mesotheliomas and negative in adenocarcinomas. We compared the nuclear and cytoplasmic staining patterns of WT1 in these 2 malignancies using a commercially available antibody and examined the expression of 2 other previously reported positive markers, calretinin and thrombomodulin.
Sixty-seven mesotheliomas and 51 adenocarcinomas, all paraffin embedded, were retrieved from recent case files. The diagnosis of mesothelioma was based on typical clinical and morphologic features, as well as immunohistochemistry; electron microscopy had been performed on 16 cases. The diagnosis of adenocarcinoma was based on typical light microscopic findings and a positive stain for mucin. Commercially available antibodies to WT1, thrombomodulin, and calretinin were applied. Because of the conflict surrounding calretinin, 2 anticalretinin antibodies (from Chemicon Inc and Zymed Laboratories) were utilized.
Fifty of 67 mesotheliomas showed strong nuclear staining with WT1. No adenocarcinomas (0/51) showed nuclear staining. Twenty-three of 67 mesotheliomas were positive for thrombomodulin, and 35 of 67 mesotheliomas were positive for calretinin with the Chemicon antibody. Nine of 15 mesotheliomas were positive for calretinin with the Zymed antibody.
Thrombomodulin and calretinin did not prove useful in discriminating between mesotheliomas and adenocarcinomas. The degree of positivity with calretinin may be dependent on the specific antibody utilized. Nuclear staining for WT1 is highly specific for mesothelioma and, in the appropriate clinical setting, can be a helpful adjunct in the distinction between adenocarcinomas and mesotheliomas.
既往研究表明，某些免疫组化标志物，包括WT1，可能有助于鉴别腺癌和间皮瘤，但迄今为止，尚无可靠的、被广泛接受的、可商购的在间皮瘤中呈阳性而在腺癌中呈阴性的抗体。我们使用一种可商购的抗体比较了WT1在这两种恶性肿瘤中的核染色和胞质染色模式，并检测了另外2种先前报道的阳性标志物钙视网膜蛋白和血栓调节蛋白的表达。
从近期病例档案中检索出67例间皮瘤和51例腺癌，均为石蜡包埋。间皮瘤的诊断基于典型的临床和形态学特征以及免疫组化；16例进行了电子显微镜检查。腺癌的诊断基于典型的光镜表现和黏液阳性染色。应用了可商购的针对WT1、血栓调节蛋白和钙视网膜蛋白的抗体。由于围绕钙视网膜蛋白存在争议，使用了2种抗钙视网膜蛋白抗体（来自Chemicon公司和Zymed实验室）。
67例间皮瘤中有50例WT1核染色强阳性。51例腺癌均未显示核染色。67例间皮瘤中有23例血栓调节蛋白阳性，67例间皮瘤中有35例使用Chemicon抗体时钙视网膜蛋白阳性。15例间皮瘤中有9例使用Zymed抗体时钙视网膜蛋白阳性。
血栓调节蛋白和钙视网膜蛋白在鉴别间皮瘤和腺癌方面并无帮助。钙视网膜蛋白的阳性程度可能取决于所使用的特异性抗体。WT1的核染色对间皮瘤具有高度特异性，在适当的临床背景下，可作为鉴别腺癌和间皮瘤的有用辅助手段。
