What is a liver hemangioma?

Liver Hemangioma: Definition and Management

A liver hemangioma is the most common benign liver tumor consisting of clusters of blood-filled cavities lined by endothelial cells and fed by the hepatic artery. 1, 2 These vascular malformations are typically asymptomatic and discovered incidentally during imaging studies performed for unrelated reasons.

Epidemiology and Characteristics

• Prevalence: 0.4% to 8% of the general population 1
• Female predominance: Female to male ratio of up to 5:1 1
• Classification by size:
  • Small: Few mm to 3 cm
  • Medium: 3-10 cm
  • Giant: >10 cm 2, 3

Pathophysiology

Liver hemangiomas are developmental vascular malformations rather than true neoplasms. They consist of:

• Blood-filled cavities lined by endothelial cells
• Blood supply from the hepatic artery
• Lack of portal venous supply 4

Clinical Presentation

• Asymptomatic: Most hemangiomas (>50%) are found incidentally 2, 5
• Symptomatic: When symptoms occur, they typically include:
  • Right upper quadrant abdominal pain (most common symptom, especially in lesions >5 cm)
  • Feeling of fullness or early satiety
  • Nausea or vomiting (with larger lesions)

Imaging Characteristics

Ultrasound

• Small lesions (<2 cm): Uniformly echogenic
• Medium lesions (2-5 cm): Predominantly echogenic
• Large lesions (>5 cm): Mixed echogenicity 4

Contrast-Enhanced Ultrasound (CEUS)

• Peripheral nodular enhancement (74%) in arterial phase
• Complete (78%) or incomplete (22%) centripetal filling in portal venous and late phases
• Diagnostic accuracy: 80-90% 4, 1

MRI

• High signal intensity on T2-weighted images
• Peripheral nodular enhancement with progressive centripetal filling on dynamic contrast sequences
• Accuracy: 95-99% for hemangioma diagnosis 1
• Superior for lesion characterization in uncertain cases 4

Management Approach

Asymptomatic Hemangiomas

• Small to medium (<5 cm): No specific treatment or routine follow-up required 1
• Medium to large (5-10 cm): Annual ultrasound monitoring 1
• Giant (>10 cm): Ultrasound monitoring every 6 months 1

Symptomatic Hemangiomas

Intervention should be considered for:

• Progressive abdominal pain (most common indication)
• Rapid growth
• High-risk features (peripheral location, exophytic growth)
• Size >10 cm with symptoms 1, 3

Treatment Options

1. Surgical resection: Preferred for symptomatic lesions >5 cm 3, 6

   • Enucleation is the preferred surgical technique with fewer complications than formal hepatectomy 5, 6

2. Non-surgical options:

   • Transarterial embolization
   • Radiofrequency ablation (limited role for smaller symptomatic lesions) 1

Special Considerations

Pregnancy

• Pregnancy is not contraindicated with liver hemangiomas
• For hemangiomas >5 cm: Ultrasound monitoring each trimester
• For hemangiomas >10 cm: More vigilant monitoring due to 5% rupture risk 1

Complications

• Rupture risk: <1% for small lesions, 3.2% for giant hemangiomas (5-10 cm), 5% for lesions >10 cm 1
• Kasabach-Merritt syndrome (disseminated intravascular coagulation): Rare but requires intervention 6

Follow-up

• Post-surgical: Imaging at 3 months to confirm complete resection
• No long-term follow-up needed after complete resection 1

Important Caveats

• Liver biopsy should be avoided if imaging strongly suggests hemangioma due to bleeding risk 1
• Atypical hemangiomas can mimic malignant lesions such as hepatocellular carcinoma or cholangiocarcinoma, requiring careful radiological assessment 7
• Always rule out other causes of abdominal symptoms before attributing them to hemangioma 5

Liver hemangiomas generally follow a benign course, with less than 40% showing progression over time 5. The management approach should be guided by the presence of symptoms, size of the lesion, and associated risk factors.