Liver enlargement is professionally referred to as hepatomegaly. This condition accompanies many diseases and it is usually quite inconspicuous sign. The patient himself may not experience any difficulties and enlarged liver may be found incidentally during routine medical examination. The liver is located in the right upper abdominal quadrant right under the diaphragm. In normal circumstances liver can not be palpated. Enlarged liver tissue is, however, examinable by palpation and percussion in area below the right costal arch.
There are many possible causes of liver enlargement, only the most common and most important shall be mentioned in this article. Very often these causative factors are various types of liver inflammation.
Infectious processes affecting liver tissue are usually associated liver enlargement in acute phase of inflammations. This is typical in viral infectious hepatitis A-E and infectious mononucleosis. Even bacterial infections can lead to enlargement of the liver; in particular when bacterial abscesses emerge in liver tissue. Enlargement of the liver caused by fungal or parasitic infection (e.g. echinococcus cyst) is quite rare in developed countries, but it can not be primarily excluded.
Liver tissue may be affected by cancer developing from liver cells (liver cancer – hepatocellular carcinoma), but this is not so common. Enlargement of liver caused by metastases of other tumors is more usual. There is a distinct blood flow through liver tissue and that is why there is also bigger risk of tumor cells invasion. Liver metastases are typical for tumors of digestive tract (stomach cancer, colorectal cancer, pancreatic cancer, gallbladder cancer, etc.) and gynecological tumors. Large metastases are often palpable as rigid nodes. Liver tissue is also often affected by “blood cancers”, i.e. tumors developing from blood cells such as leukemia and lymphoma.
Note: There is a benign affection that can cause liver enlargement and may mimic hepatocellular carcinoma. It is known as focal nodular hyperplasia and it usually occurs in young women.
There are many conditions causing liver cirrhosis, for example alcoholism, Wilson’s disease, hemochromatosis, autoimmune hepatitis, some chronic types of infectious hepatitis (especially B and C), primary biliary cirrhosis, primary sclerosing cholangitis and alpha 1-antitrypsin deficiency (see relevant text about liver cirrhosis). Especially in some forms of cirrhosis we can palpate enlarged liver with cirrhotic nodules and ragged liver edge. It should be noted, however, that long-term cirrhosis leads to a gradual diminution of the liver tissue and so we find small liver in advanced liver cirrhosis.
Inflammation of the liver tissue caused by alcohol is one of most common forms of alcoholic liver damage. It can have various severity, the most severe forms can manifest by symptoms of acute liver failure.
Liver tissue filled with blood is usually related with liver enlargement. We find this condition in right-sided heart failure when blood accumulates in the inferior vena cava and the liver veins. A non-serious form of mild liver congestion may occur in untrained people during physical exertion causing abdominal pain in upper right abdominal quadrant.
Liver enlargement itself may be relatively asymptomatic, only sometimes it manifests with a feeling of pressure or abdominal pain in the right upper quadrant of abdomen and loss of appetite. If there is present significant disturbance of liver function, affected person may experience symptoms such as jaundice, hepatic encephalopathy, bleeding disorders, etc. Malignant diseases affecting the liver may cause general warning symptoms such as night sweats, recurrent fever, sudden weight loss, etc.
Liver enlargement may be primarily found by physical examination (palpation, percussion). Palpation is important for approximate estimation of liver size (centimeters or inches beyond the right lower costal arch) and evaluation of liver edge quality (hard, soft, rough, sensitive to palpation, etc). Physical examination must be followed by imaging methods. Abdominal ultrasound is the most accessible, yet cheap method that can be followed by computed tomography. Blood tests can show us presence of liver damage (elevated liver tests) and presence of inflammation in the body (elevated CRP). Serologic tests can diagnose certain viral liver infections. There is also a highly specific serum tumor marker for liver cancer known as alpha-fetoprotein (AFP).
In case we find an unknown focus in liver, sometimes it is possible to perform liver biopsy to get a tissue sample for histological examination.