Diagnostic Ultrasound - Abdomen and Pelvis

Echogenic Liver Mass
• Fibrolamellar Carcinoma
○ Large heterogeneous mass in adolescent or young adult
○ Well-defined and partially or completely encapsulated
mass
○ Prominent central fibrous scar (hypo- or hyperechoic)
– Calcification within scar common
○ Intratumoral necrosis/hemorrhage
○ Background cirrhosis or hepatitis in < 5% of patients
• Amebic Hepatic Abscess
○ Usually homogeneous and hypoechoic
– Hyperechoic if complicated by bacterial superinfection
or bowel fistula
○ Low-level internal echoes due to debris
○ Peripheral location: Abuts liver capsule, under diaphragm
• Hepatic Angiomyolipoma (AML)
○ Homogeneous/heterogeneous echogenic mass
– Hyperechoic due to fat
○ May be hypoechoic if muscle, vascular elements, or
hemorrhage predominate
• Biliary Hamartoma
○ Numerous small hypo/hyperechoic foci uniformly
distributed throughout liver
– When small, appear hyperechoic due to inability to
resolve tiny cysts
– Leads to inhomogeneous and coarse appearance of
liver echotexture
○ Multiple echogenic foci
– Often with associated "comet tail" artifacts
○ Typically smaller lesions appear as echogenic foci,
whereas larger lesions appear cystic
– Extent of echogenic foci on US is greater than
anticipated, based on comparison CT or MR
• Hepatic Hydatid/Echinococcus Cyst
○ Membranes ± daughter cysts in complex heterogeneous
mass
○ Anechoic cyst with internal debris, hydatid sand
○ E. multilocularis
– Single or multiple echogenic lesions
– Irregular necrotic areas and microcalcifications
– Infiltrative solid masses
– Invasion of IVC and diaphragm
• Hepatic Epithelioid Hemangioendothelioma (HEHE)
○ Variable echogenicity pattern
– Predominantly hypoechoic
– Hyper-/isoechoic lesions; may have peripheral
hypoechoic rim
○ Often associated with adjacent retracted capsule
• Hepatic Lipoma
○ Extremely uncommon lesion
○ Contain mature adipose tissue
Alternative Differential Approaches
• Vascular masses
○ Cavernous hemangioma, HCC, hemangioendothelioma,
angiosarcoma
• Fat-containing masses
○ Focal fatty infiltration, hepatic adenoma, HCC, lipidcontaining
metastases, angiomyolipoma, lipoma,
liposarcoma, teratoma (primary or metastatic to liver)
• Gas-containing masses
○ Abscess, infarction, treated hepatic tumors with
resulting sudden necrosis
• Solid masses
○ Primary liver tumors, metastases, cholangiocarcinoma
• Masses with calcified rim
○ Chronic cystic masses
• Masses with calcified scar
○ Fibrolamellar, HCC, cavernous hemangioma (large ones)
SELECTED REFERENCES
1. Bhatnagar G et al: The varied sonographic appearances of focal fatty liver
disease: review and diagnostic algorithm. Clin Radiol. 67(4):372-9, 2012
2. Kamaya A et al: Hypervascular liver lesions. Semin Ultrasound CT MR.
30(5):387-407, 2009
3. Basaran C et al: Fat-containing lesions of the liver: cross-sectional imaging
findings with emphasis on MRI. AJR Am J Roentgenol. 184(4):1103-10, 2005
4. Prasad SR et al: Fat-containing lesions of the liver: Radiologic-pathologic
correlation. Radiographics 25:321-331; 2005
Differential Diagnoses: Liver
Focal Steatosis
Hepatic Cavernous Hemangioma
(Left) Abdominal grayscale
ultrasound shows focal fat
deposition as geographic areas
of increased echogenicity ſt
around portal vein . The
lesion shows no mass effect
and vessels run through the
lesion, features that are
helpful in the diagnosis of
focal steatosis. (Right)
Transverse high-frequency
ultrasound of the liver shows a
well-defined, homogeneously
echogenic cavernous
hemangioma st.
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