Diagnostic Ultrasound - Abdomen and Pelvis

Multiple Hepatic Masses
886
Differential Diagnoses: Liver
DIFFERENTIAL DIAGNOSIS
Common
• Hepatic Cysts
• Hepatic Metastases
• Hepatic Steatosis (Multifocal)
• Hepatic Hemangioma
• Hepatic Lymphoma (Discrete Form)
• Cirrhosis With Regenerative/Dysplastic Nodules
• Hepatocellular Carcinoma
• Pyogenic Hepatic Abscess
• Hepatic Microabscesses
• Cholangitis
• Vessels
Less Common
• Hepatic Echinococcus Cyst
• Hepatic Hematoma
• Biliary Hamartoma
Rare but Important
• Caroli Disease
ESSENTIAL INFORMATION
Helpful Clues for Common Diagnoses
• Hepatic Cysts
○ Uncomplicated simple cyst
– Anechoic rounded
– Smooth or lobulated borders
– Posterior acoustic enhancement
– Thin or nondetectable wall
– No septation/mural nodule/wall calcification
○ Hemorrhagic or infected cyst
– Internal debris (clots or fibrin strands)
– Septations/thickened wall,± calcification
○ Autosomal dominant polycystic liver disease
– Numerous cysts
– Anechoic or with debris due to hemorrhage or
infection
– Calcification of some cyst walls
– May have barely perceptible septations
– No mural nodularity
– Liver often distorted by innumerable cysts
– Look for presence of renal cysts (adult polycystic
kidney disease)
○ Do not demonstrate saccular configuration
– vs. Caroli disease
○ Not associated with biliary duct dilatation
– vs. hydatid cysts or Caroli disease
• Hepatic Metastases
○ Hypoechoic necrotic metastases
– Usually from hypovascular tumors
– Simulate cysts or abscesses
– Abnormal intratumoral vascularity contains debris,
mural nodules, or septa
○ Hyperechoic metastases
– Simulate hemangioma or focal steatosis
– Distort vessels and bile ducts
– Vascular metastasis; from neuroendocrine tumors,
choriocarcinoma, renal cell carcinoma, melanoma
○ Target metastatic lesions
– Solid echogenic mass with hypoechoic rim or halo
– Usually from aggressive primary tumors
○ Cystic metastasis
– May demonstrate posterior acoustic enhancement
– Mural nodules, thick walls, fluid-fluid levels, internal
septa, or debris
○ Calcified metastasis
– Markedly echogenic interface with acoustic
shadowing or diffuse small echogenic foci
– Treated metastasis
• Hepatic Steatosis (Multifocal)
○ Focal fatty infiltration
– Location: Right lobe, caudate lobe, perihilar
– Hyperechoic area
○ Focal fatty sparing
– Location: Gallbladder bed, segment 4 anterior to
portal bifurcation
– Hypoechoic areas within echogenic liver
○ Geographic or fan-shaped
○ In some cases may appear as multiple echogenic nodules
throughout liver
○ No mass effect
○ Vessels run undisplaced through lesion
• Hepatic Hemangioma
○ Well-defined margins
○ Hyperechoic mass, typically homogeneous
○ Posterior acoustic enhancement
○ Atypical features
– Hypoechoic± hyperechoic rim
– Heterogeneous, calcification, irregular borders
• HepaticLymphoma (Discrete Form)
○ Well-defined nodules or masses
○ Hypoechoic or anechoic
– Low echogenicity due to high cellular density
○ Large/conglomerate masses may appear to contain
septa
– Mimic abscesses
○ Background vascular architecture ± distortion
○ More common in immunocompromised patients
– e.g., AIDS patients and organ transplant recipients
• Cirrhosis With Regenerative/Dysplastic Nodules
○ Coarse echo pattern, increased parenchymal
echogenicity, other signs of cirrhosis
○ Regenerating nodules (siderotic)
– Iso-/hypoechoic nodules (regenerating nodules)
– Hyperechoic rim (surrounding fibrosis)
○ Dysplastic nodules
– Hypoechoic nodule > 1 cm diameter
– Smooth or irregular borders
– Difficult to differentiate from small hepatocellular
carcinoma
□ Should be further investigated with CECT or MR
• Hepatocellular Carcinoma
○ Most commonly hypoechoic
– Less commonly hyperechoic or isoechoic to liver
○ Irregular hypervascularity within mass
○ Cirrhotic background liver
○ May see portal vein invasion or tumor thrombosis
• Pyogenic Hepatic Abscess