Brown sclerosis of the lung: long-term pulmonary congestion, fibrous tissue proliferation in the interstitium of the lungs, and a thin texture. The lung tissue turns brown due to the deposition of hemosiderin.

Heart failure cells: Pulmonary congestion can occur when the left heart fails. During chronic pulmonary congestion, edema fluid accumulates in the alveolar cavity, often containing a small number of red blood cells and macrophages. The macrophages phagocytose the red blood cells and decompose the hemoglobin in the red blood cells into brown-yellow granular hemosiderin. This phagocytosis Cells containing hemosiderin are called heart failure cells.

Liver congestion may occur in right heart failure, and long-term liver congestion may occur. In the cross section of the liver, it can be seen that the congestion areas in the center of adjacent liver lobules are connected to each other, forming a red and yellow pattern-like structure, which resembles the cut surface of a betel nut, so it is called "betel nut liver" (liver lobule). The central congestion is dark red; the peripheral fat of the liver lobules turns grayish yellow)