Hepatocellular carcinoma (HCC)

Hepatocellular carcinoma (HCC)

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver, originating from hepatocytes (the main functional cells of the liver). It typically occurs in the setting of chronic liver disease, especially cirrhosis due to chronic hepatitis B or C infection, alcoholic liver disease, or non-alcoholic fatty liver disease (NAFLD/NASH).
HCC

• Risk Factors
• Symptoms
• Sonographic Diagnostic clue
• Prognosis

Risk Factors

• Chronic liver disease/cirrhosis (most common background for HCC):
• Hepatitis B virus (HBV) (even without cirrhosis)
• Hepatitis C virus (HCV)
• Alcoholic liver disease
• Non-alcoholic fatty liver disease (NAFLD) / non-alcoholic steatohepatitis (NASH)
• Aflatoxin exposure (contaminated grains, especially in Asia/Africa)
• Genetic conditions:
• Hemochromatosis
• Alpha-1 antitrypsin deficiency
• Wilson’s disease

Symptoms

Often asymptomatic in early stages. When present:

• Weight loss
• Right upper quadrant abdominal pain
• Jaundice
• Ascites
• Hepatomegaly or a palpable mass
• Decompensation of cirrhosis (new or worsening)

Sonographic Diagnostic clue

Morphological types HCC
1. Nodular HCC

Appears as a discrete, round or oval mass.

Can be solitary or multiple.

May show a "halo sign" on imaging.

Can be solitary or multiple.

Small nodules (less than 2 cm)show a peripheral halo or appear hypoechoic/ hyperechoic with smooth or irregular margins.

Larger HCCs often display the classic mosaic pattern—different internal densities, occasional halo, and possibly posterior acoustic enhancement

Hypoechoic halo sign:

Definition: A peripheral hypoechoic rim surrounding a hepatic lesion.

Seen in:

• Hepatocellular carcinoma (HCC)
• Metastases
• Occasionally in benign lesions like hemangiomas or focal nodular hyperplasia, though less commonly.

Significance:

• Often represents a tumor capsule, compressed liver parenchyma, or inflammatory response.
• In HCC, it may be an indicator of capsular invasion or malignant potential.

2. Massive HCC

Large, single mass that may occupy a major portion of the liver.

May have necrotic or hemorrhagic areas.

Often with satellite nodules.

A large, heterogeneous, ill-defined mass lesion is noted in the right hepatic lobe, measuring approximately 8.9 × 6.3 cm. The lesion appears predominantly hypoechoic with areas of internal necrosis and peripheral vascularity. Features are suggestive of a massive hepatocellular carcinoma (HCC). Underlying liver shows coarse echotexture consistent with cirrhosis. No intrahepatic biliary dilatation.
Optional Add-ons (if CEUS or Doppler is used):
Contrast-enhanced ultrasound (CEUS): Early arterial phase hyperenhancement with mild, late washout—consistent with HCC.
Doppler study: Demonstrates chaotic internal arterial flow with low-resistance waveform.

1. B-mode (gray-scale) Ultrasound

Large HCC generally appears as a solid, heterogeneous mass—often hypoechoic (darker) or mixed echogenic—and with ill-defined margins.

2. Morphologic Classification

Massive HCC belongs to the “massive” growth type, typically >5 cm, often with necrotic areas and irregular borders.

3. Vascular Features on Doppler/CEUS

Doppler: Chaotic, irregular arterial flow within the tumor (low-resistance waveform).

CEUS:

• Arterial phase (10–30 s): Bright uptake (hyperenhancement) due to abnormal neovascularity.
• Portal/late phase (~60 s): Mild “washout” (relatively hypoechoic), helping differentiate HCC from benign nodules or cholangiocarcinoma.

4. Clinical Context

Massive HCC typically arises in cirrhotic or chronically diseased livers and often presents late, sometimes with vascular invasion or satellite nodules.

Feature	Description
Size & Texture	Large (>5 cm), heterogeneous, often hypoechoic
Margin	Irregular, not well demarcated
Vascular Behavior	Arterial hyperenhancement → slow, mild washout
Typical Context	Cirrhosis or chronic liver disease

Note: Ultrasound serves as a vital first-line screening tool for liver cancer, complemented by CEUS to characterize suspicious lesions in real-time.

3. Infiltrative HCC

Ill-defined margins, spreads diffusely through the liver.

Difficult to detect early on ultrasound.

Associated with vascular invasion (e.g., portal vein tumor thrombus).

Liver is enlarged with coarse echotexture. A large, ill-defined, heterogeneously hypoechoic region is noted in the right hepatic lobe, extending across multiple segments with no discrete margins measures of 5.3 x 4.6 cm.—suggestive of infiltrative hepatocellular carcinoma (HCC). No well-defined capsule or focal mass is seen. Features are concerning for diffuse hepatic tumor infiltration.
Optional (if Doppler/CEUS/clinical context is available):

Consider Doppler/CEUS to evaluate vascular involvement and enhancement pattern

Underlying liver parenchyma may suggest cirrhosis.

Sonographic Features of Infiltrative HCC

1. Ill‑defined, Geographic Hypoechoic Areas

Rather than a distinct nodule, infiltrative HCC often appears as a diffuse, heterogeneous, hypoechoic region blending into the cirrhotic liver—frequently described as geographic or poorly demarcated.

2. Multiple Small Tumor Foci and Satellite Nodules

Clusters or satellites of small tumor nodules are typically dispersed throughout a hepatic segment or lobe, making the lesion radiologically difficult to discern as a focal mass.

3. Vascular Invasion (Portal Vein Involvement)

Infiltrative HCC often invades vessels, presenting with echogenic tumor thrombus within portal veins, which may demonstrate abnormal flow on Doppler or contrast imaging. Some cases show thrombus extension into the portal system.

4. Contrast‑Enhanced Ultrasound (CEUS) Patterns

• Arterial phase: Early, patchy or geographic hyperenhancement throughout affected segments.
• Portal/late phase: Subtle washout, often less pronounced than in focal HCC, sometimes absent.

Case series images reveal arterial-phase hypervascularity in both the liver parenchyma and tumor thrombus, with subsequent washout.

📋 Summary Table of Infiltrative HCC on Ultrasound

Feature	Description
Echotexture	Geographic, heterogeneous, hypoechoic area
Margins	Ill-defined, blending into cirrhotic parenchyma
Tumor Nodules	Multiple small foci, often widespread in a segment
Vascular Invasion	Portal vein tumor thrombus, echogenic vascular mass
CEUS Behavior	Early hyperenhancement, mild-to-moderate washout
Detection Difficulty	Easily obscured in cirrhosis due to diffuseness

Clinical Implications

High index of suspicion is required in cirrhotic patients presenting with new geographic liver changes, rising AFP, or portal vein thrombus. CEUS is especially valuable for real-time visualization of atypical enhancement patterns and early tumor vascularity. Accurate detection demands thorough scanning technique, high-quality imaging equipment, and expert sonographic interpretation.

Based on Number of Lesions

Unifocal HCC: Single lesion.

Multifocal HCC: Multiple distinct nodules.

Diffuse HCC: Numerous small nodules, often indistinct.

Unifocal HCC: Single lesion.

B-mode ultrasound images of unifocal HCC (a single lesion) showing typical features:

Feature Summary

Feature	Description
Nodule	Solitary, well-defined
Echotexture	Heterogeneous, often hypoechoic (± halo)
Size	Usually >2 cm (can be smaller)
Vascular invasion	Uncommon in focal type
CEUS enhancement pattern	Arterial hyper, portal/late washout

Multifocal HCC: Multiple distinct nodules.

B‑mode ultrasound images demonstrating multifocal HCC—multiple distinct nodules in the liver.
Fig:A-

• Demonstrates two well-defined hypoechoic nodules separated by normal tissue—classic multifocal presentation

Fig:B-

• Multiple small, heterogeneous hypoechoic to isoechoic lesions scattered across the liver, demonstrating size and echogenic variation

Fig:C-

• Larger hypoechoic nodule seen alongside smaller satellite lesions—bi-lobar involvement possible in advanced disease .

Fig:D-

• Dense cluster of nodules with varied echotexture; coexisting portal flow abnormalities may suggest vascular invasion .

USG Feature	Description
Nodule pattern	Multiple distinct lesions in one or both lobes
Echotexture	Heterogeneous, hypoechoic or mixed
Size variability	Nodules of differing sizes; may be satellite clusters
Vascular invasion	Possible in larger foci; check portal/hepatic veins
CEUS enhancement	Arterial hyperenhancement → portal/late washout
Clinical impact	Suggests intermediate/advanced HCC with complex management

Special Variants (Histopathological)

Fibrolamellar HCC: Occurs in young adults without liver disease; central scar may be seen.

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Clear cell HCC: Composed of clear cytoplasm cells; better prognosis.

The liver isoechoic mass with a hypoechoic rim in segment 7, with a microlobulated surface. The lesion did not have a lateral shadow and had slightly posterior echo enhancement.

Color flow Doppler images displayed inflow of the blood flow signal, which indicated that the lesion was hypervascular.

Fig: (A) Plain CT of the liver displaying a low-density mass with a maximum diameter of 30 mm on segment 7.

Fig: (B) Dynamic enhanced CT displaying a ring-like enhancement in the arterial phase.

Fig: (C) In the equilibrium phase, an enhancing capsule was observed, and the center of the lesion was slightly enhanced.

Scirrhous HCC: Abundant fibrous stroma, hypoechoic on ultrasound.

The liver parencyma shows two hepatic masses, one measured 6.7 × 6 cm in segment 8 and another of 6 × 5.5 cm in segment 7. The tumor in segment 8 was characterized by a well-defined and hemorrhagic foci, whereas the tumor in segment 7

Steatohepatitic (SH) HCC: Contains fat droplets; may mimic benign steatosis.

A heterogeneous hepatic lesion in 7th segment with focal fatty components and internal vascularity, suggestive of steatohepatitic HCC.

Prognosis

• Strongly dependent on stage at diagnosis and liver function
• Without treatment, median survival may be 6 months.
• With early detection and curative treatment, 5-year survival can exceed 70%.