Abstract
Thymic epithelial cells of cortex and medulla were studied by histological, morphometric, and immunohistochemical analysis. Epithelial cells in the cortex had large round nuclei with fine chromatin and conspicuous nucleoli. Those in the medulla had oval to spindle-shaped nuclei with irregular margins, coarse chromatin, and inconspicuous nucleoli. The nuclear area of epithelial cells in the cortex was significantly larger than in the medulla. Immunohistochemical studies showed that the epithelial cell in the outer cortex contained Leu7 and keratin, while those in the inner cortex and in the medulla contained keratin but no Leu7. These results show that the epithelial cells of the cortex and medulla differ histologically, morphometrically, and immunohistochemically.
