ABSTRACT
The thymus is a triangular bilobed structure enclosed in a thin fibrous capsule and located retrosternally (Figure 9.1 and Figure 9.2). Each lobe is subdivided by prominent trabeculae into interconnecting lobules, and each lobule comprises two histologically and functionally distinct areas, cortex and medulla (Figure 9.3). The cortex consists of a mesh of epithelial reticular cells enclosing densely packed large lymphocytes (called thymocytes). It has no germinal centers.
