Hepatic hemangiomas

Hepatic hemangiomas

Hepatic hemangiomas (HH) are the most common benign tumors of the liver. These tumors are made up of blood-filled spaces lined by a single layer of flat endothelial cells and are fed by the hepatic arterial circulation. They are often discovered incidentally during imaging studies for other conditions. While most hepatic hemangiomas are asymptomatic and require no treatment, understanding their nature, potential complications, and management options is necessary to be provided for patients diagnosed with this condition.

What are hepatic hemangiomas?

Hepatic hemangiomas are vascular malformations that can vary greatly in size, ranging from as small as 1 mm to as large as 50 cm. They are typically well-defined, hypervascular lesions and are more commonly found in women. The prevalence of hepatic hemangiomas ranges from 0.4% to 7.3% based on autopsy findings, and they are found in 0.4%-20% of the general population.

Types of hepatic hemangiomas

Hepatic hemangiomas are classified into three types based on their nature:

1. Cavernous hemangiomas: The most common type, characterized by large, blood-filled spaces.
2. Capillary hemangiomas: Composed of smaller blood vessels.
3. Sclerosing hemangiomas: Characterized by degeneration and fibrous replacement, which can sometimes be mistaken for malignant tumors.

How do hepatic hemangiomas develop?

The exact cause of hepatic hemangiomas is not fully understood. However, they are believed to arise from vascular malformations that grow due to the dilation of blood vessels rather than cellular hypertrophy or hyperplasia. Some studies suggest a genetic predisposition, and abnormal angiogenesis (the formation of new blood vessels) may play a role.

Role of hormones

Hormones, particularly estrogens, are thought to influence the growth of hepatic hemangiomas. These tumors are more frequently observed in women, and their size can increase during pregnancy, hormone replacement therapy (HRT), or with the use of oral contraceptive pills (OCPs). However, hepatic hemangiomas do not have estrogen or progesterone receptors, and the exact mechanisms by which hormones affect their growth remain unclear.

Hepatic hemangiomas: Symptoms

Most hepatic hemangiomas are asymptomatic and are often discovered incidentally during imaging for other conditions. However, when symptoms do occur, they are usually related to the size of the tumor.

Common symptoms

• Abdominal Pain or Discomfort: Often felt in the right upper quadrant due to stretching and inflammation of the liver’s capsule (Glisson’s capsule).
• Abdominal Distention: Particularly in cases of very large tumors (>10 cm).
• Nausea, Early Satiety, and Postprandial Bloating: Caused by pressure on adjacent structures.

Rare but serious complications

• Kasabach-Merritt Syndrome: A life-threatening condition characterized by thrombocytopenia (low platelet count), disseminated intravascular coagulation (DIC), and systemic bleeding. This is more common in giant hemangiomas (>15 cm).
• Spontaneous or Traumatic Rupture: Although rare (0.47% risk), this can lead to significant internal bleeding.

Do hepatic hemangiomas grow over time?

The natural progression of hepatic hemangiomas varies. While they were once thought to remain stable, recent studies have shown that some hemangiomas can grow over time. Growth rates are generally slow, with larger hemangiomas (>5 cm) showing a higher likelihood of increasing in size. Younger patients (under 30 years) and those with initial hemangioma sizes of 8-10 cm tend to experience faster growth rates.

Hepatic hemangiomas: Diagnosis

Hepatic hemangiomas are typically diagnosed through imaging studies. The choice of imaging depends on the characteristics of the lesion and the clinical context.

Imaging modalities

1. Ultrasound (US): Often the first imaging test due to its availability. Hepatic hemangiomas appear as well-defined, hyperechoic masses with posterior acoustic enhancement.
2. Contrast-Enhanced Ultrasound (CEUS): Improves characterization by showing peripheral nodular enhancement in the early phase with centripetal filling in later phases.
3. Computed Tomography (CT): Shows hypodense masses with peripheral nodular enhancement and centripetal filling when contrast is used.
4. Magnetic Resonance Imaging (MRI): Considered the best imaging method, with high sensitivity and specificity. Hepatic hemangiomas appear hypointense on T1-weighted images and hyperintense on T2-weighted images.
5. Angiography: Used for atypical cases, showing a “snowy-tree” or “cotton wool” appearance with diffuse pooling of contrast.

Biopsy: Not recommended

Needle aspiration biopsy is generally not recommended due to the high risk of hemorrhage and low diagnostic yield.

Hepatic hemangiomas: Treatment

Most hepatic hemangiomas are asymptomatic and do not require treatment. However, management may be necessary in certain situations.

Observation

• Small, Asymptomatic Hemangiomas: No treatment or follow-up is needed.
• Larger Hemangiomas (>5 cm): Some experts recommend periodic imaging (every 6-12 months) to monitor for growth.

Treatment indications

Treatment is considered for:

• Symptomatic patients.
• Rapidly growing tumors.
• Compression of adjacent organs (e.g., gastric outlet obstruction, Budd-Chiari syndrome).
• Complications such as rupture or Kasabach-Merritt syndrome.

Surgical options

1. Liver Resection: Removal of the affected part of the liver.
2. Enucleation: Removal of the hemangioma while preserving surrounding liver tissue.
3. Hepatic Artery Ligation: Tying off the artery supplying the hemangioma.
4. Liver Transplantation: Reserved for unresectable giant hemangiomas causing severe symptoms or life-threatening complications.

Non-surgical options

1. Transcatheter Arterial Embolization (TAE): Used to shrink the hemangioma or control bleeding by blocking the blood supply.
2. Radiofrequency Ablation (RFA): Uses heat to destroy the tumor. Suitable for smaller hemangiomas.
3. Medications: Anti-VEGF drugs (e.g., sorafenib, bevacizumab) and metformin have been reported to reduce hemangioma size in some cases, though more research is needed.

Living with hepatic hemangiomas

Most hepatic hemangiomas are benign and asymptomatic, requiring no treatment. When symptoms do occur, they are usually related to the size of the tumor and its effect on surrounding structures. In such cases, a variety of treatment options are available, ranging from minimally invasive procedures to surgery.

Patients with hepatic hemangiomas should be reassured that the condition is generally benign. Regular monitoring may be recommended for larger hemangiomas, but most patients can live normal, healthy lives without intervention. If treatment is necessary, advances in medical and surgical techniques offer effective options with minimal risk.

Future research will continue to improve our understanding of hepatic hemangiomas, leading to better management strategies and outcomes for patients. If you have been diagnosed with a hepatic hemangioma, your gastroenterologist will determine the best course of action tailored to your needs.

How can I contact gastroenterologist Dr. Zavos for an appointment?

Dr. Chris Zavos is a board-certified gastroenterologist and hepatologist, located in Thessaloniki Greece, and specifically in Kalamaria suburb, about 7 kilometres (4 miles) southeast of downtown Thessaloniki. His private office is at: Fanariou 8 street (near Aigaiou and Adrianoupoleos avenues), Kalamaria (Thessaloniki), Greece.

Thessaloniki International Airport is only 10 km away from his private office in Kalamaria and can be reached by taxi within 13 minutes from the airport.

Dr. Chris Zavos performs endoscopies at Bioclinic private hospital in downtown Thessaloniki (Mitropoleos 86 street).

You can contact Dr. Zavos at phone numbers: (+30)-6976596988 and (+30)-2311283833, or you can email him at czavos@ymail.com. Dr. Zavos responds to Greek and English languages.