Nutmeg liver

Associate Editor:

Nutmeg liver is the pathological appearance of the liver caused by chronic passive congestion of the liver secondary to right heart failure. The liver appears "speckled" like a grated nutmeg kernel, from the dilated, congested central veins (dark spots) and paler, unaffected surrounding liver tissue. When severe and longstanding, hepatic congestion can lead to cirrhosis, a state described as cardiac cirrhosis.

Etiology
Increased pressure in the sublobular branches of the hepatic veins causes an engorgement of venous blood, and is most frequently due to chronic cardiac lesions, especially those affecting the right heart, the blood being dammed back in the inferior vena cava and hepatic veins. Central regions of the hepatic lobes are red/brown and stand out against the non-congested tan colored liver. Centrilobular necrosis occurs. Macroscopically liver has a pale and spotty appearance in affected areas as stasis of the blood causes pericentral hepatocytes (liver cells surrounding the periportal venules of the liver) to become deoxygenated compared to the relatively better oxygenated periportal hepatocytes adjacent to the hepatic arterioles. This retardation of the blood also occurs in pulmonary lesions, such as chronic interstitial pneumonia, pleural effusions, and intrathoracic tumors.

Symptoms
These depend largely upon the primary lesions giving rise to it. In addition to the cardiac or pulmonary symptoms, there will be a sense of fullness and tenderness in the right hypochondriac region. Gastro-intestinal catarrh is usually present, and hematemesis may occur. There is usually more or less jaundice. Owing to portal obstruction, ascites occurs, followed later by general dropsy. The stools are light or clay colored, and the urine is colored by bile. On palpation, the liver is found enlarged and tender, sometimes extending several inches below the costal margin of the ribs.

Treatment
This is directed largely to removing the cause, or, where that is impossible, to modifying its effects. Thus hygienic and dietary measures must be carried out, even although it is due to valvular lesions.

Pathological Findings
Images shown below are courtesy of Professor Peter Anderson DVM PhD and published with permission. © PEIR, University of Alabama at Birmingham, Department of Pathology