Pyogenic liver abscesses usually develop following peritonitis due to leakage of intraabdominal bowel contents that subsequently spread to liver via the portal circulation or via direct spread from biliary infection. They may also result from arterial hematogenous seeding in the setting of systemic infection.
The clinical approach to pyogenic liver abscess will be reviewed here. Amebic abscesses are discussed separately. (See "Extraintestinal Entamoeba histolytica amebiasis".)
Prevalence — Liver abscesses are the most common type of visceral abscess; in a report of 540 cases of intraabdominal abscesses, pyogenic liver abscesses accounted for 48 percent of visceral abscesses and 13 percent of intraabdominal abscesses . The annual incidence of liver abscess has been estimated at 2.3 cases per 100,000 populations and is higher among men than women (3.3 versus 1.3 per 100,000) [2-4]; substantially higher rates have been reported in Taiwan (17.6 cases per 100,000) .
Risk factors — Risk factors include diabetes, underlying hepatobiliary or pancreatic disease, and liver transplant [2,3,6,7]. Geographic and host factors may also play a role; for example, a primary invasive liver abscess syndrome due to K. pneumoniae has been described in East Asia. This is discussed separately. (See "Invasive liver abscess syndrome caused by Klebsiella pneumoniae".)
Association with colorectal neoplasia — Several studies from Asia, where K. pneumoniae is the primary cause of pyogenic liver abscesses, have suggested an association with underlying colorectal cancer [8-13]. It is unclear whether these findings can be applied to other parts of the world.