Definition and EtiologyTop
Hepatomegaly is the term used to describe an enlarged liver. Depending on the body build, a normal liver is either not palpable or its lower border is palpable immediately below the costal margin. Liver enlargement is evidenced by an increase in the area of liver dullness on percussion, which normally extends to 12 cm in women and to 15 cm in men in the midclavicular line.
Etiology: Hepatomegaly may be associated with:
1) Inflammation: Mainly viral hepatitis, drug-induced liver disease, steatosis (alcoholic, nonalcoholic), systemic bacterial or viral infection, cirrhosis (early stages; in more advanced cirrhosis the liver is small), autoimmune hepatitis, primary biliary cirrhosis, sarcoidosis, liver abscess.
2) Congestion: Right ventricular failure, hepatic vein occlusion (thrombosis, sinusoidal obstruction syndrome).
3) Cholestasis: Extrahepatic biliary obstruction (choledocholithiasis, pancreatic cancer, cancer of the ampulla of Vater).
4) Liver infiltrates: Lymphoma, leukemia, extramedullary hematopoiesis.
5) Storage disorders: Hemochromatosis (inherited or acquired), amyloidosis, glycogenosis, lipidosis (eg, Gaucher disease), Wilson disease.
6) Tumors: Hepatocellular carcinoma, metastasis.
A palpable edge of the liver below the costal margin is not always a sign of hepatomegaly. Ultrasonography (or computed tomography [CT], if there are additional indications) allows for assessing liver size, structure, blood vessels, and bile ducts, as well as detecting features of portal hypertension. Further diagnostic workup depends on the suspected cause.