In normal and hyperplastic thymi CD25(+)/Foxp3(+) cells were located mainly in the medulla, and their number was not influenced by the presence of MG. Foxp3(+) and CD25(+) cells were significantly less numerous in thymomas.
Flow cytometric analysis revealed an increasing number of CD3+/CD25+ lymphocytes in the peripheral blood, and the resected thymoma had infiltrated lymphocytes with CD4/CD8/CD25 antigens.