Localized pus collection in liver due to Entamoeba histolytica with destruction of hepatic parenchyma

General feature

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  Most often solitary (85%), peripherally located

Ultrasound

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  Sharply demarcated, round or ovoid mass

  
  
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  Hypoechoic with low-level internal echoes

  
  
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  May see internal septa or wall nodularity

  
  
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  May see posterior acoustic enhancement

CECT

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  Typically hypoattenuating unilocular lesion

  
  
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  Peripheral rim or capsule enhancement

  
  
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  May see hypodense halo due to edema

Hepatic metastasis (post treatment, cystic, or necrotic)

Hepatic pyogenic abscess

Hepatic hydatid cyst

Biliary cystadenoma/cystadenocarcinoma

Infarcted liver after transplantation

Entamoeba histolytica

Primary source of infection: Human carriers passing amebic cysts into stool

Right upper quadrant pain, tender hepatomegaly, diarrhea with mucus

Indirect hemagglutination positive in 90% of cases

Rule out pyogenic or fungal abscess, cystic lesions

Check for history of transplantation, ablation, or chemotherapy for liver tumor or metastasis, which may simulate amebic abscess on imaging