Thymus cortex (mouse, young adult)

Electron microscopy. Surrounded by thymocytes (2) a cortical macrophage (starry-sky macrophage) is seen and shows an electron-light nucleus (N) and a distinct nucleolus. The cell has engulfed two apoptotic thymocytes (1). The cytoplasm also contains small electron-dense lysosomes and myelin figures (-->). (3) shows a cross-section of an epithelioreticular cell type II with small granules-filled vacuoles and intermediate filaments (keratin filaments, *)