The thymus is composed of mainly hematopoietic thymocytes and nonhematopoietic thymic epithelial cells
Morimoto et al., "Aire expression is inherent to most medullary thymic epithelial cells
during their differentiation program," Journal of Immunology, vol.
As we know it, the positive and negative selections of thymocytes are mediated by thymic epithelial cells
(TECs), the predominant component in the thymic microenvironment.
Thymoma is a rare tumor of thymic epithelial cells
, with an estimated incidence of 0.13 cases per 100 000 persons per year.
Thymomas are anterior mediastinal tumors that originate from the thymic epithelial cells
. These tumors are histologically benign and have been traditionally classified as predominantly lymphocytic, predominantly epithelial, mixed lymphocytic and epithelial, and spindle cell thymoma. Another histogenetic classification scheme proposed by Marino and Muller-Hermelink and elaborated by Quintanilla-Martinez and colleagues is based on the resemblance of the neoplastic cells to various normal thymic epithelial cells
Antibody to factor VIII-related antigen highlighted the endothelium of feeding vessels, but failed to stain the small endothelial cells of the tumor Residual thymic epithelial cells
stained positively for cytokeratin using the CAM 5.2 antibody (Figure 3).