A localised collection of pus within the liver. The most frequently seen cause is an intestinal infection. Bacteria can spread from those areas inflamed by appendicitis or diverticulitis, and amoebae can invade the liver as a direct result of amoebiasis. Symptoms are pain in upper right abdomen, fever, and (particularly in the elderly) confusion.
Ultrasound scanning generally exposes the abscess, and the organism responsible can be identified by investigation of a tissue or blood sample. The abscess can occasionally be treated through aspiration (sucking out the pus through a needle), but usually surgery is necessary.