Hepatomegaly refers to an increase in size or enlargement of the liver.
Hepatomegaly can result from a vast range of pathology including, but not limited to, the following:
- malignancy/cellular infiltrate
- acquired hepatic conditions
- acquired non-hepatic conditions
- congenital anomalies
Assessment of liver size is commonly made on ultrasound or CT, although gross hepatomegaly may be apparent on abdominal radiograph.
For the adult liver:
- midclavicular line averages 10-12.5 cm in craniocaudal length 2
- a liver that is longer than 15.5 cm in the midclavicular line is considered enlarged
- average transverse diameter is 20-23 cm at the level of the upper pole of the right kidney 2
In practice, however, assessment is often subjective.
Features that support hepatomegaly include 1:
- extension of the right lobe inferior to the lower pole of the right kidney
- rounding of the hepatic inferior border
- Riedel's lobe (normal variant)