A 55-year-old diabetic man presents with fever, rigors, and right upper quadrant pain for 7 days. Contrast-enhanced CT of the abdomen shows multiple small hypodense lesions in the right lobe of the liver that have coalesced into a larger collection with enhancing internal septa, producing the 'cluster sign'. The MOST likely diagnosis is:

• A Biliary cystadenoma
• B Amebic liver abscess
• C Cystic hepatic metastases
• D Pyogenic liver abscess ✓

Explanation

The 'cluster sign' (multiple small abscesses coalescing into a larger loculated collection with septal enhancement) is characteristic of pyogenic liver abscess on CT. Amebic abscess is typically solitary, unilocular, and lacks internal septa in early stages. Cystic metastases do not show the cluster sign or significant perilesional edema. Biliary cystadenoma is multilocular but lacks fever and systemic signs of infection.

Reference: Abdominal Imaging (Federle), Standard edition ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.