Amebic Hepatic Abscess

KEY FACTS

Terminology

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

Imaging

  • General feature

    • Most often solitary (85%), peripherally located

  • Ultrasound

    • Sharply demarcated, round or ovoid mass

    • Hypoechoic with low-level internal echoes

    • May see internal septa or wall nodularity

    • May see posterior acoustic enhancement

  • CECT

    • Typically hypoattenuating unilocular lesion

    • Peripheral rim or capsule enhancement

    • May see hypodense halo due to edema

Top Differential Diagnoses

  • Hepatic metastasis (post treatment, cystic, or necrotic)

  • Hepatic pyogenic abscess

  • Hepatic hydatid cyst

  • Biliary cystadenoma/cystadenocarcinoma

  • Infarcted liver after transplantation

Pathology

  • Entamoeba histolytica

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

Clinical Issues

  • Right upper quadrant pain, tender hepatomegaly, diarrhea with mucus

  • Indirect hemagglutination positive in 90% of cases

Scanning Tips

  • 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

Graphic illustration demonstrates a unilocular encapsulated amebic abscess within the liver. Note the surrounding rim of edema and central anchovy paste consistency of contents .

Sagittal grayscale ultrasound of the liver shows a large, well-demarcated and encapsulated hypoechoic amebic abscess . The contents are heterogeneous due to floating debris . Also note the mild posterior acoustic enhancement .

Nov 10, 2024 | Posted by in ULTRASONOGRAPHY | Comments Off on Amebic Hepatic Abscess

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