Kraus V B, Harden E A, Wittels B, Moore J O, Haynes B F
Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27707.
Am J Pathol. 1988 Sep;132(3):552-62.
A panel of monoclonal antibodies that phenotypically define stages of normal human thymic epithelial (TE) cell maturation was used to compare thymic epithelium of nine thymomas with hyperplastic thymic epithelium in myasthenia gravis (MG) and thymic epithelium of normal thymuses. It has been shown previously that normal thymic epithelial cells express antigens of early TE cell maturation (A2B5, TE-4) throughout thymic ontogeny and acquire antigens 12/1-2, TE8, and TE-15 at 14 to 16 weeks of fetal gestation. Hyperplastic MG thymic epithelial cells expressed TE antigens in phenotypic patterns similar to that seen in normal postnatal thymus, ie, TE in subcapsular cortex and medulla was TE4+, A2B5+, and 12/1 - 2+ and Hassall's bodies were reactive with antibodies TE8 and TE15. In contrast, thymic epithelium in primary mediastinal thymomas was TE4+, A2B5+, TE8-, and greater than 75% of thymoma epithelium was 12/1 - 2-, a thymic epithelial phenotype similar to that seen on normal fetal thymic epithelium at 14 to 16 weeks fetal gestation. In one subject with a mature epithelial histologic pattern, thymoma epithelium was found to be strongly TE8+, a phenotype suggestive of a later stage of TE maturation. Lymphocytes in five of seven thymomas with immature thymic epithelial cells predominantly expressed immature thymocyte phenotype while two thymomas with immature epithelial phenotype showed a predominance of Langerhans cells and surrounding lymphocytes expressing a mature phenotype. Lymphocytes in the thymoma with differentiated epithelial cells expressed a mature thymocyte phenotype. Thus, in thymomas of varying histologic types, phenotypic abnormalities of thymic epithelium are present; these phenotypic abnormalities may reflect abnormal thymic epithelial maturation.
一组从表型上定义正常人胸腺上皮（TE）细胞成熟阶段的单克隆抗体被用于比较9例胸腺瘤的胸腺上皮与重症肌无力（MG）患者增生性胸腺上皮以及正常胸腺的胸腺上皮。先前已表明，正常胸腺上皮细胞在整个胸腺发育过程中表达早期TE细胞成熟抗原（A2B5、TE-4），并在胎儿妊娠14至16周时获得抗原12/1-2、TE8和TE-15。增生性MG胸腺上皮细胞以与正常出生后胸腺中所见相似的表型模式表达TE抗原，即被膜下皮质和髓质中的TE为TE4+、A2B5+和12/1 - 2+，且哈氏小体与抗体TE8和TE15反应。相比之下，原发性纵隔胸腺瘤中的胸腺上皮为TE4+、A2B5+、TE8-，且超过75%的胸腺瘤上皮为12/1 - 2-，这种胸腺上皮表型与胎儿妊娠14至16周时正常胎儿胸腺上皮所见相似。在一名具有成熟上皮组织学模式的受试者中，发现胸腺瘤上皮强烈表达TE8+，这一表型提示TE成熟的后期阶段。7例胸腺上皮细胞不成熟的胸腺瘤中有5例的淋巴细胞主要表达不成熟胸腺细胞表型，而2例具有不成熟上皮表型的胸腺瘤显示朗格汉斯细胞和周围表达成熟表型的淋巴细胞占优势。具有分化上皮细胞的胸腺瘤中的淋巴细胞表达成熟胸腺细胞表型。因此，在不同组织学类型的胸腺瘤中，存在胸腺上皮的表型异常；这些表型异常可能反映胸腺上皮成熟异常。
