Hassall's corpuscles are a characteristic feature of the thymus (40X)

Histologically, the cortex ot the thymic lobules is teeming with thymocytes, macrophages, and epithelial cells. The medulla, on the other hand, features fewer thymocytes but introduces dendritic cells and the enigmatic Hassall's corpuscles; round structures that seem important but mostly just sit there. Hassall's corpuscles are a characteristic feature of this organ. They have no known function and are likely epithelial cells undergoing degeneration.