1、胸腺瘤（纵膈病变）,正常胸腺组织学,The cortex is composed of an extensive population of T cell precursors (also called thymocytes), dispersed epithelial reticular cells, and macrophages. Because the cortex is richer in small lymphocytes than the medulla, it stains more darkly. The epithelial reticular cells are stel
2、late cells with light-staining oval nuclei. They are usually joined to similar adjacent cells by desmosomes . Bundles of intermediate keratin filaments (tonofibrils) in their cytoplasm are evidence of the epithelial origin of these cells. A subpopulation of epithelial reticular cells present in the
3、cortex consists of thymic nurse cells (TNCs), which contain many (20100) maturing lymphocytes in their cytoplasm.,胸腺组织从青春期后开始经历正常的退化过程,Section of the thymus of an elderly adult. Severe atrophy of the parenchyma, which was partially replaced by adipose tissue, can be seen. PT stain. Low magnification,胸腺瘤(thymomas)的分型,胸腺癌（C型胸腺瘤），根据分化来命名鳞状细胞癌、粘液表皮样癌等,纵膈常见的淋巴瘤：T细胞来源的淋巴瘤相对多见，B细胞来源的很少见（一）前驱T淋巴母细胞性淋巴瘤/白血病（二）胸腺B细胞淋巴瘤：1，纵膈大B细胞淋巴瘤 2，霍奇金淋巴瘤，结节硬化型,thanks,
