This 74 year-old female presented with right upper quadrant pain and fever. CT demonstrates a large irregular fluid-density lesion within the right lobe of the liver with rim enhancement. There are multiple smaller peripheral lesions with similar characteristics. Some of these appear coalescent. This is the typical appearance for a pyogenic liver abscess.
Percutaneous CT-guided drainage was performed. A heavy growth of Streptococcus milleri was grown.

The most common organisms found in pyogenic liver abscess are Staphylococcus aureus in children and Escherichia coli in adults. Differential diagnoses include: amoebic abscess; hydatid cyst; cystic metastasis; and biliary cystadenocarcinoma.

Reference: Federle MP, et al. Diagnostic Imaging: Abdomen Amirsys 2004
Credit: Dr Laughlin Dawes