20. Induratio fusca pulmonis (HE)

20. Induratio fusca pulmonis (HE)
The process demonstrates the local deposition of haemosiderin in the lungs in chronic left heart failure (especially in congenital or acquired in later defects of the mitral valve). As a result of chronic venous stasis in the alveolar capillary wedge there is hypoxia, which leads to damage of endothelial cells and their permeability to increase. By diapedeza erythrocytes appear in the lumen of the alveoli, where phagocytosed by macrophages located there, in this case denoted as hemosiderofagi. In their hemoglobin is converted into ferritin, which aggregates in zlatistokafenikavite hemosiderin granules. Meanwhile, hypoxia leads to proliferation of fibroblasts to produce collagen and thickening of the
епидермис alveolar walls. In the alveoli and the interstitial are many hemosiderofagi. Hemosiderofagite can be found in the sputum of patients as a diagnostic test and therefore are called cells of the heart defect (Hertzfehlercellen)