Fogel M, Lifschitz-Mercer B, Moll R, Kushnir I, Jacob N, Waldherr R, Livoff A, Franke W W, Czernobilsky B
Department of Pathology, Kaplan Hospital, Rehovot, Israel.
Differentiation. 1990 Dec;45(3):242-9. doi: 10.1111/j.1432-0436.1990.tb00478.x.
Testicular seminoma has in the past been considered to represent a germ cell tumor incapable of further differentiation. In recent years this view has been challenged on the basis of morphologic and chromosomal studies. Moreover, studies of intermediate filaments (IF) of seminoma cells have provided evidence of the capability of seminoma cells to differentiate in different directions. In the present study of the IF protein profile of 26 human testicular seminomas, using frozen as well as formalin-fixed, paraffin-embedded tissues, we report evidence of a heterogeneous differentiation potential inherent in these neoplasms. Thus, in 4 of the seminomas neither cytokeratins nor vimentin were detected; 3 showed vimentin positive cells but no cytokeratins; in 4 seminomas only cytokeratins were detected. In the remaining 15 cases both cytokeratins and vimentin were present, with occasional cells demonstrating coexpression of cytokeratin and vimentin. While the cytokeratins present were mostly of the "simple epithelial type", in 2 instances seminoma cells also contained cytokeratins 4 and 17, normally found in stratified and/or complex glandular epithelia. Furthermore, in 3 cases scattered tumor cells stained for desmin and in 2 other seminomas neurofilaments were identified. All of the cases showed variable positive staining for desmoplakins and desmoglein, indicative of the presence of desmosomes. It can therefore be concluded that, while some seminomas seem to be devoid of IFs, most of them show varied differentiation patterns usually with epithelial features but occasionally also with components commonly regarded as characteristic of myogenic or neurogenic differentiation. These observations may help to elucidate the relationship of seminomas to other germ cell tumors, and also contribute to our understanding of the histogenesis of these neoplasms.
过去，睾丸精原细胞瘤被认为是一种无法进一步分化的生殖细胞肿瘤。近年来，基于形态学和染色体研究，这一观点受到了挑战。此外，对精原细胞瘤细胞中间丝（IF）的研究提供了证据，表明精原细胞瘤细胞具有向不同方向分化的能力。在本研究中，我们使用冷冻以及福尔马林固定、石蜡包埋的组织，对26例人类睾丸精原细胞瘤的IF蛋白谱进行了研究，报告了这些肿瘤中存在异质性分化潜能的证据。因此，在4例精原细胞瘤中，未检测到细胞角蛋白和波形蛋白；3例显示波形蛋白阳性细胞，但未检测到细胞角蛋白；在4例精原细胞瘤中，仅检测到细胞角蛋白。在其余15例病例中，细胞角蛋白和波形蛋白均存在，偶尔有细胞同时表达细胞角蛋白和波形蛋白。虽然存在的细胞角蛋白大多为“简单上皮型”，但在2例中，精原细胞瘤细胞还含有通常在复层和/或复杂腺上皮中发现的细胞角蛋白4和17。此外，在3例病例中，散在的肿瘤细胞结蛋白染色阳性；在另外2例精原细胞瘤中，鉴定出了神经丝。所有病例均显示桥粒斑蛋白和桥粒芯糖蛋白呈不同程度的阳性染色，表明存在桥粒。因此可以得出结论，虽然一些精原细胞瘤似乎缺乏中间丝，但大多数精原细胞瘤表现出不同的分化模式，通常具有上皮特征，但偶尔也具有通常被认为是肌源性或神经源性分化特征的成分。这些观察结果可能有助于阐明精原细胞瘤与其他生殖细胞肿瘤的关系，也有助于我们理解这些肿瘤的组织发生。
