Liver Hemangioma
A liver hemangioma is the most common benign liver tumor, characterized by clusters of blood-filled cavities lined by endothelial cells and fed by the hepatic artery, with a prevalence ranging from 0.4% to 7.3% and a female-to-male ratio of up to 5:1. 1, 2
Characteristics and Pathophysiology
- Liver hemangiomas are developmental malformations that are usually of no clinical significance 3
- They consist of thin-walled blood vessels lined by endothelial cells that are fed solely by the hepatic arterial system 3
- Hemangiomas lack portal venous supply, which distinguishes them from some other liver lesions 4
- They are more common in women, suggesting possible hormonal influence 2
Appearance on Imaging
On B-mode ultrasound, appearance varies by size 3:
- Small hemangiomas (<2 cm): Typically appear uniformly echogenic
- Medium hemangiomas (2-5 cm): Mainly echogenic
- Large hemangiomas (>5 cm): Show mixed echogenicity patterns
On contrast-enhanced imaging, hemangiomas show characteristic features 3:
- Peripheral nodular enhancement (74%) in arterial phase
- Complete (78%) or incomplete (22%) centripetal filling in portal venous and late phases
- This "filling-in" pattern is highly specific for hemangioma diagnosis
Clinical Presentation
The vast majority of hemangiomas are asymptomatic and discovered incidentally during imaging for unrelated conditions 5
When symptomatic, the most common presentation is right upper quadrant abdominal pain, typically in larger lesions that cause distension of Glisson's capsule 5, 6
Giant hemangiomas (>10 cm) may cause symptoms due to mass effect, including 7, 6:
- Abdominal distension
- Early satiety
- Compression of adjacent structures
Rarely, complications may occur, particularly with giant hemangiomas 8:
- Kasabach-Merritt syndrome (consumptive coagulopathy)
- Rupture (risk increases to approximately 5% in lesions >10 cm) 2
Diagnosis
- Contrast-enhanced ultrasound (CEUS) is highly effective for confirming diagnosis with a specific diagnostic rate of 82.2% for hemangiomas 3
- MRI with contrast is the preferred next imaging modality when ultrasound findings are inconclusive, with accuracy of 95-99% 1
- Biopsy is generally not recommended due to risk of bleeding and is only necessary when imaging is inconclusive and malignancy cannot be excluded 1
Management
Most hemangiomas require no treatment regardless of size, as they rarely grow or cause complications 1, 2
Routine surveillance is not required for patients with typical-appearing hemangiomas on ultrasound 1
Intervention is indicated only in specific circumstances 1, 2:
- Symptomatic lesions causing pain or compression of adjacent structures
- Rapidly enlarging lesions
- Complications such as rupture
- Uncertainty of diagnosis when malignancy cannot be excluded
For giant hemangiomas (>10 cm), especially in women planning pregnancy, discussion about potential treatment prior to conception may be considered due to slightly increased risk of complications 2
Special Considerations
- Pregnancy is not contraindicated in women with hepatic hemangiomas, even giant ones 2
- Close monitoring with ultrasound is recommended during pregnancy for women with giant hemangiomas 2
- Diffuse hepatic hemangiomas in children can lead to severe complications, including high-output cardiac failure, but this is not applicable to typical solitary hemangiomas in adults 1
Treatment Options When Indicated
Surgical options include 7, 6:
- Enucleation (preferred when feasible as it results in less blood loss and shorter operative time)
- Liver resection (for very large lesions or when enucleation is not technically feasible)
Pre-operative transcatheter arterial embolization may be considered to reduce tumor volume before resection of giant hemangiomas 8