Raica Marius, Encică Svetlana, Motoc Andrei, Cîmpean Anca Maria, Scridon Traian, Bârsan Mircea
Department of Histology, Victor Babes University of Medicine and Pharmacy, Piata Eftimie Murgu 2, 300041 Timisoara, Romania.
Ann Anat. 2006 Jul;188(4):345-52. doi: 10.1016/j.aanat.2006.01.012.
The study was conducted on 27 specimens of normal thymus, removed during surgery for cardiovascular malformations. Biopsies were processed using current histological techniques, and the samples were stained using morphological and immunohistochemical methods (cytokeratin profile, vimentin, S100, CD45, CD20, CD3, CD68, CD34 protein, chromogranin A, neuronal-specific enolase, desmin). Microscopic examination focused on the structure and immunohistochemical profile of Hassall corpuscles, beginning from the hypothesis that the epithelial cells of these structures, characteristic for the thymus, participate in the negative and positive selection of thymocytes. Morphological assessment revealed the existence of four different types of Hassall corpuscles: juvenile, immature, mature and senescent. The lymphocyte-rich variant was identified in 25.92% of the cases with ages ranging between 7 days and 12 years. From the immunohistochemical point of view, the following reactions were negative: cytokeratins 7 and 8, vimentin, desmin, CD3, CD68, CD34 and neuron-specific enolase. Isolated positive chromogranin cells were found in two cases, and positive intracorpuscular CD20 cells in one case. Polyclonal cytokeratins were positive in all instances in the epithelial cells of the Hassall corpuscles, with higher intensity in high-molecular weight cytokeratin, strongly expressed in mature corpuscles. All specimens had positive S100 cells in the corpuscles, distributed among the epithelial cells, with dendritic morphology, in great numbers in juvenile and immature forms. Morphological and immunohistochemical results (corpuscle variants, the presence of positive S100 cells, concentration of positive CD20 and CD3 cells around the corpuscles) suggest the active involvement of epithelial cells of Hassall corpuscles in modulating the differentiation of thymocytes at the medullar level, a process that is mediated by protein S100 positive corpuscular dendritic cells.
该研究对27例正常胸腺标本进行，这些标本是在心血管畸形手术中切除的。活检采用当前的组织学技术进行处理，样本用形态学和免疫组织化学方法（细胞角蛋白谱、波形蛋白、S100、CD45、CD20、CD3、CD68、CD34蛋白、嗜铬粒蛋白A、神经元特异性烯醇化酶、结蛋白）进行染色。显微镜检查聚焦于哈氏小体的结构和免疫组织化学特征，始于这样的假设：这些结构的上皮细胞是胸腺的特征性细胞，参与胸腺细胞的阴性和阳性选择。形态学评估揭示了四种不同类型的哈氏小体的存在：幼年型、未成熟型、成熟型和衰老型。在年龄介于7天至12岁之间的病例中，25.92%发现了富含淋巴细胞的变体。从免疫组织化学角度来看，以下反应为阴性：细胞角蛋白7和8、波形蛋白、结蛋白、CD3、CD68、CD34和神经元特异性烯醇化酶。在两例中发现了孤立的嗜铬粒蛋白阳性细胞，在一例中发现了哈氏小体内CD20阳性细胞。多克隆细胞角蛋白在哈氏小体的上皮细胞中均呈阳性，在高分子量细胞角蛋白中强度更高，在成熟小体中强烈表达。所有标本的小体内均有S100阳性细胞，分布在上皮细胞之间，呈树突状形态，在幼年型和未成熟型中数量众多。形态学和免疫组织化学结果（小体变体、S100阳性细胞的存在、小体周围CD20和CD3阳性细胞的浓度）表明，哈氏小体的上皮细胞积极参与调节髓质水平胸腺细胞的分化，这一过程由S100阳性小体树突状细胞介导。
