Analysis of the histogenesis of thymoma

我们用免疫组织化学方法检查了胸腺瘤。A型胸腺瘤（14例）仅由pCK+/EMA-/VM)-/CDN-1+呼梭形上皮细胞组成。也没有发现TCDM。化生性胸腺瘤（1例）是A型胸腺瘤的pCK+/VM-/EMA-/CDN-1+肿瘤细胞和pCK-/VM+/EMA+/CDN-1-成纤维样化生上皮细胞（FMECs）的嵌合体。在大多数AB型胸腺瘤（19例中有14例）中，a型样区由fmec组成。其余5例均为A型胸腺瘤细胞组成。这些结果表明AB型胸腺瘤有两种不同的亚型，化生型AB型胸腺瘤和常规型AB型胸腺瘤。B型胸腺瘤中存在相当数量的TCDM，肿瘤细胞β5t免疫反应性表明B型胸腺瘤基本为c- tec肿瘤。我们还发现B3型胸腺瘤有两种亚型，含TCDM的分化亚型和含TCDM的间变性亚型，尽管它们之间的临床关系尚不清楚。我们还发现B3型胸腺瘤可以通过适当使用thy/TCDM、β5t、c-Kit和/或CD5等标记物与胸腺癌区分开来

We examined thymomas immunohitochemically. Type A thymoma (14 cases) were composed solely of pCK+/EMA-/VM)-/CDN-1+ shout spindle epithelial cells. Thy nor TCDM were not found at all. Metaplastic thymoma (1 case) was found to be mosaic of two different components, pCK+/VM-/EMA-/CDN-1+ tumor cells of type A thymoma and pCK-/VM+/EMA+/CDN-1- fibroblastoid metaplastic epithelial cells (FMECs). In the majority of type AB thymoma (14 of 19 cases), type A-like areas were composed of FMECs. In contrast, type A-like areas of remaining 5 cases were composed of type A thymoma cells. These findings indicate that there are two different subtypes in type AB thymoma, metaplastic type AB thymoma and conventional type AB thymoma. The presence of a considerable numbers of TCDM in types B thymomas and β5t-immunoreactivity of tumor cells indicates that type B thymomas are basically tumor of c-TECs. We also found that there are two subtypes of type B3 thymoma, the differentiated subtype containing TCDM and the anaplastic subutype lucking TCDM, although clinical between them remains unclear. We also found that type B3 thymoma are able to be distinguished from thymic carcinoma by proper use of markers such as thy/TCDM, β5t, c-Kit and/or CD5