Nutmeg liver.

The term “Nutmeg” refers to the appearance of liver in chronic venous congestion which resembles the appearance of speckled nutmeg Kernel
Etiology: Most common cause is right heart failure. Other causes include obstruction of blood flow in hepatic vein and inferior venacava.
Pathogensis: Due to right heart failure, there is increased pressure in the hepatic veins. Hepatic veins are congested and stasis of blood causes deoxygenation of hepatocytes. Centrilobular hemorrhagic necrosis occurs which is surrounded by paler zone which contains damaged hepatocytes with fatty change. Adjacent to this zone normal unaffected hepatocytes are present which are adjacent to hepatic arteriole and are better oxygenated.
Morphology
Gross: Liver is enlarged and firm in consistency. Cut section shows alternating red areas representing congested and dilated hepatic vein and paler areas of fatty change giving the appearance of Nutmeg kernel.
Microscopy :
- Dilated and congested hepatic veinules with centrilobular hemorrhagic necrosis of hepatocytes.
- Periphery shows fatty change in hepatocytes
- Hepatocytes adjacent to portal triad are normal.
- Later fibrosis may develop and condition is called as “Cardiac Cirrhosis”