Mori Kanji, Chano Tokuhiro, Kushima Ryoji, Hukuda Sinsuke, Okabe Hidetoshi
Department of Orthopedic Surgery, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga, 520-2192, Japan, Japan.
Department of Clinical Laboratory Medicine, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga, 520-2192, Japan, Japan.
Virchows Arch. 2002 Feb;440(2):123-127. doi: 10.1007/s004280100525.
Chordoma is a relatively rare malignant bone tumor thought to arise from the remnants of the fetal notochord. Chordomas express epithelial cell markers such as cytokeratin and epithelial membrane antigen (EMA), which strongly suggests that the tumor cells grow via the mechanism of epithelial characterized cell-cell interactions. However, there are no known reports that have studied epithelial characterized cell-adhesion molecules such as E-cadherin or epithelial cell adhesion molecule (Ep-CAM) in chordomas. An immunohistochemical investigation was performed in seven cases of chordoma to determine the expression of pan-cytokeratin, Ep-CAM, and E-cadherin. Histological specimens showed the typical appearance of conventional chordoma but for two cases of chondroid chordoma. Cytokeratin was constantly expressed in conventional chordomas, but it was detected among a few cells with physaliphorous appearance in chondroid chordoma cases. Although no Ep-CAM expression was noted, E-cadherin was detected in most chordoma cells irrespective of histological subtypes. The expression of E-cadherin was negative among chondrosarcoma cells in this study as previously reported, and thus constant E-cadherin expression of chordoma cells suggests a role as a useful diagnostic marker to distinguish chondroid chordoma from chondrosarcoma. Furthermore, we speculate that E-cadherin may play a role in tumor cell adhesion and is also involved with histological and clinical features in chordomas.
脊索瘤是一种相对罕见的恶性骨肿瘤，被认为起源于胎儿脊索的残余部分。脊索瘤表达上皮细胞标志物，如细胞角蛋白和上皮膜抗原（EMA），这强烈表明肿瘤细胞通过上皮特征性的细胞间相互作用机制生长。然而，尚无已知报道研究脊索瘤中上皮特征性的细胞黏附分子，如E-钙黏蛋白或上皮细胞黏附分子（Ep-CAM）。对7例脊索瘤进行了免疫组织化学研究，以确定全细胞角蛋白、Ep-CAM和E-钙黏蛋白的表达情况。组织学标本显示为典型的传统脊索瘤外观，但有2例为软骨样脊索瘤。细胞角蛋白在传统脊索瘤中持续表达，但在软骨样脊索瘤病例中，仅在少数具有泡状外观的细胞中检测到。虽然未观察到Ep-CAM表达，但无论组织学亚型如何，大多数脊索瘤细胞中均检测到E-钙黏蛋白。如先前报道，本研究中软骨肉瘤细胞中E-钙黏蛋白表达为阴性；因此，脊索瘤细胞中E-钙黏蛋白的持续表达表明其可作为区分软骨样脊索瘤和软骨肉瘤的有用诊断标志物。此外，我们推测E-钙黏蛋白可能在肿瘤细胞黏附中起作用，并且也与脊索瘤的组织学和临床特征有关。
