What is the recommended approach for the surveillance of liver hemangiomas?

Surveillance of Liver Hemangiomas

For typical liver hemangiomas, routine surveillance is not required as they generally follow a benign course and rarely require intervention unless they are giant (>5 cm), symptomatic, or show rapid growth. 1

Diagnostic Confirmation

• Typical hemangiomas have characteristic imaging features on ultrasound with small hemangiomas (<2 cm) appearing uniformly echogenic, medium hemangiomas (2-5 cm) mainly echogenic, and large hemangiomas (>5 cm) showing mixed echogenicity 2, 1
• Contrast-enhanced ultrasound (CEUS) is highly effective for confirming diagnosis with typical findings of peripheral nodular enhancement (74%) in arterial phase and complete (78%) or incomplete (22%) centripetal filling in portal venous and late phases 2, 1
• When ultrasound findings are inconclusive, MRI with contrast is the preferred next imaging modality due to its high accuracy (95-99%) for diagnosing hemangiomas 1
• Biopsy is generally not recommended for suspected hemangiomas due to risk of bleeding and is only necessary when imaging is inconclusive and malignancy cannot be excluded 2, 1

Surveillance Algorithm Based on Size

Small to Medium Hemangiomas (<5 cm)

• No routine surveillance is required for asymptomatic, typical-appearing hemangiomas 1, 3
• No intervention is needed during pregnancy or when using hormonal contraception 2, 1

Giant Hemangiomas (>5 cm)

• Periodic surveillance with ultrasound is recommended to assess for growth or development of symptoms 1, 3
• Giant hemangiomas have an increased risk of complications, with a risk of hepatic rupture of approximately 3.2%, which increases to 5% in lesions >10 cm 1, 4
• Peripherally located and exophytic lesions have a higher rupture risk and may warrant more frequent monitoring 1

Special Surveillance Considerations

During Pregnancy

• For small to medium hemangiomas (<5 cm), no special monitoring is required during pregnancy 2
• For giant cavernous hemangiomas (>5-10 cm), ultrasound monitoring during each trimester of pregnancy is recommended due to potential growth from hormonal changes and increased blood volume 2, 1
• For women with giant hemangiomas (>10 cm) planning pregnancy, discussion about potential treatment prior to conception should be considered 2, 1

Atypical Hemangiomas

• Atypical features on ultrasound that warrant closer surveillance include lobulated margins, chunky calcifications, heterogeneity indicating hemorrhage or necrosis, and diminished vascularity 5
• These lesions may require more frequent imaging follow-up to ensure stability 5

Indications for Intervention

• Intervention is indicated for:
  • Symptomatic lesions causing pain or compression of adjacent structures 1, 3
  • Rapidly enlarging lesions 1, 6
  • Complications such as rupture or Kasabach-Merritt syndrome (rare consumptive coagulopathy) 3, 6
  • When diagnosis remains inconclusive despite imaging 3

Practical Approach to Surveillance

• For nodules <1 cm in a cirrhotic liver, follow-up ultrasound at 4-month intervals in the first year is recommended; if stable, return to 6-month intervals thereafter 2
• For typical hemangiomas in non-cirrhotic livers, no specific surveillance is needed 1
• If a previously diagnosed hemangioma shows growth or change in enhancement pattern during follow-up, additional imaging or biopsy may be warranted 2

Common Pitfalls and Caveats

• Cavernous hemangiomas may show hypointensity on the equilibrium phase of dynamic Gd-EOB DTPA MRI (pseudo-wash-out), which should not be mistaken for malignancy 2
• High-flow hemangiomas can show rapid enhancement in the arterial phase and may be mistaken for hepatocellular carcinomas or focal nodular hyperplasia if the nodular pattern and centripetal flow direction are not recognized 2
• Sonazoid® CEUS has low specificity for distinguishing hemangiomas from other lesions as both hemangiomas and other lesions like hepatocellular carcinomas lack Kupffer cells 2

By following these evidence-based surveillance recommendations, clinicians can appropriately monitor liver hemangiomas while avoiding unnecessary imaging or interventions for these typically benign lesions.