What is a liver hemangioma?

Liver Hemangioma: Explanation and Management

Liver hemangiomas are benign vascular tumors consisting of blood-filled cavities lined by endothelial cells and fed by the hepatic artery, which typically require no intervention unless they are large (>5 cm) and symptomatic. 1

What is a Liver Hemangioma?

Liver hemangiomas are the most common benign liver tumors with a prevalence of 0.4% to 8% in the general population 1. They have a strong female predominance with a female-to-male ratio of up to 5:1 1. These vascular lesions consist of clusters of blood-filled cavities lined by endothelial cells and are fed by the hepatic artery 2.

Key Characteristics:

• Most are asymptomatic and discovered incidentally during imaging for unrelated conditions
• Typically solitary but can be multiple
• Size ranges from a few millimeters to over 20 cm in rare cases
• Classified by size:
  • Small: <3 cm
  • Medium: 3-10 cm
  • Giant: >10 cm

Diagnostic Features

Liver hemangiomas have characteristic imaging features that allow for accurate diagnosis:

• Ultrasound: First-line imaging modality showing a well-defined, homogeneously hyperechoic lesion 1
• Contrast-Enhanced Ultrasound (CEUS): Shows peripheral nodular enhancement in arterial phase with progressive centripetal filling, correctly characterizing 80-90% of hemangiomas 1, 3
• MRI: Most sensitive and specific test showing:
  • High signal intensity on T2-weighted images
  • Early peripheral nodular enhancement with progressive centripetal filling on dynamic contrast sequences
  • 95-99% accuracy for hemangioma diagnosis 1
• CT: Four-phase CT is diagnostic in 82.6% of cases, showing peripheral nodular enhancement with progressive centripetal filling 4

Management Approach

Management is based primarily on size and symptoms:

Asymptomatic Hemangiomas:

• Conservative management is recommended regardless of size 1
• No specific dietary or activity restrictions are necessary 1
• Follow-up based on size:
  • Small (<5 cm): No specific follow-up required
  • Medium (5-10 cm): Annual ultrasound monitoring
  • Giant (>10 cm): Ultrasound every 6 months 1

Symptomatic Hemangiomas:

• Most common symptom is right upper quadrant abdominal pain (due to distension of Glisson's capsule) 2
• Intervention is indicated for:
  • Progressive abdominal pain, especially with lesions >5 cm 4
  • Rapid growth
  • High-risk features (peripheral location, exophytic growth)
  • Size >10 cm with symptoms 1

Treatment Options:

1. Surgical resection: Traditionally the main treatment for symptomatic lesions

   • Enucleation is the preferred surgical method for giant hemangiomas 5
   • Post-surgical follow-up imaging at 3 months to confirm complete resection 1

2. Transarterial embolization: Increasingly recommended as treatment of choice for symptomatic cases 6

3. Radiofrequency ablation: Limited role for smaller symptomatic lesions 1

Special Considerations

• Pregnancy: Not contraindicated in patients with liver hemangiomas, but increased monitoring is recommended for hemangiomas >5 cm (ultrasound each trimester) 1
• Estrogen: Estrogen-containing medications should be avoided as they may potentially increase hemangioma size 1
• Biopsy: Should be avoided if imaging strongly suggests hemangioma due to risk of bleeding 1
• Complications: Rupture is rare (<1% for small lesions, ~5% for lesions >10 cm) but potentially life-threatening 1, 7

When to Refer to a Specialist

• Symptomatic hemangiomas >5 cm
• Rapidly growing hemangiomas
• Atypical imaging features raising concern for malignancy
• Giant hemangiomas (>10 cm)
• Hemangiomas with complications (rupture, Kasabach-Merritt syndrome)

By understanding the nature of liver hemangiomas and following appropriate management guidelines, most patients can be reassured about the benign nature of these lesions and avoid unnecessary interventions.