Epithelioid Hemangioendothelioma

Epithelioid hemangioendothelioma (EHE) is a malignant tumor that forms from the cells that line blood vessels. It’s a very rare vascular cancer (sarcoma) that affects less than 1 in every 1 million people each year. While it can form almost anywhere in your body, it often starts in your liver, lungs or bones.

These tumors show up in different ways. EHE may present as a single tumor. Sometimes, there are lots of tumors in a single organ or in many organs. In some people, tumors are aggressive and spread fast. In others, they grow slowly and (rarely) even shrink without treatment.

Since there are so many unknowns, it’s crucial to work with healthcare providers who can tailor a treatment plan for you. This often means finding a provider with experience treating rare sarcomas.

Symptoms of epithelioid hemangioendothelioma

Many people with EHE don’t have symptoms. When they do, the most common one is pain. Other symptoms depend on where the tumor is. The most common sites are your liver, lungs and bones. But tumors can form wherever blood vessels are.

Symptoms by location may include:

• Liver: Fatigue, fever, pain in your abdomen and unexplained weight loss
• Lungs: Coughing, coughing up blood, trouble breathing or enlarged fingertips or toes (called “clubbing”)
• Bones: Bone pain, frequent fractures or breaks

Epithelioid hemangioendothelioma causes

Medical experts have found certain gene errors that lead to EHE. You don’t inherit them, so they don’t run in families. Instead, the errors happen during your lifetime. Experts aren’t sure why.

With EHE, one gene joins with another gene when it shouldn’t. Usually, the genes are WWTR1 and CAMTA1. They create the new fusion gene WWTR1-CAMTA1 that drives tumor growth. A less common fusion gene combo that leads to EHE is YAP1-TFE3. But there are other, even rarer gene fusions that can happen, too.

Knowing about these abnormal gene changes helps researchers find treatments that target them.

Risk factors

Most people diagnosed are in their early 50s. But it can affect people of all ages. Medical experts have found that the common age of diagnosis for epithelioid hemangioendothelioma may be different depending on the type of fusion gene.

It’s slightly more common in females.

How doctors diagnose this condition

Since EHE doesn’t often cause symptoms, many people learn they have a “suspicious” growth during an imaging procedure unrelated to EHE. Or you may see your healthcare provider because you have general symptoms like losing weight without trying or a cough that doesn’t get better.

Tests you may need include:

• CT scans to look for tumors in your chest, abdomen and pelvis
• MRI, to check for tumors in your liver and bones
• PET scan or whole-body MRI to check for EHE throughout your body

You’ll need a biopsy to confirm that the tumor is EHE. This step is essential since these tumors are so rare. Healthcare providers sometimes assume they’re more common tumors at first. 

How is EHE treated?

This condition is so rare that there aren’t standard treatment guidelines. Instead, you’ll likely work with several specialists with experience in treating sarcomas. They’ll help you decide which treatments you need and when.

Since these tumors sometimes grow slowly (or even get better on their own), you may not need treatment if you don’t have symptoms. Instead, your provider may monitor you for changes. This is called active surveillance.

If you have symptoms or your provider sees signs that your condition will get worse, they’ll recommend treatments based on your situation.

Local treatments

These treatments remove or destroy tumors that are in just one part of an organ. They include:

• Surgery: Healthcare providers usually remove single tumors. Sometimes, they can do surgery to remove several tumors if they’re in the same region.
• Radiation therapy: You may get radiation after surgery to kill any remaining cancer cells. It may be the main treatment if you’re not able to have surgery safely.
• Vascular embolization: Your provider may cut off the tumor’s blood supply. This can happen as a standalone procedure or as a way to shrink a tumor before surgery. Types for liver EHE include transarterial chemoembolization (TACE) and radioembolization.
• Transplant: You may need a liver transplant when EHE is only in your liver but surgery isn’t an option. For instance, the tumors may be too spread out to remove safely.

Systemic therapies

You may need treatments that can kill cancer cells throughout your body if EHE is in more than one organ. This treatment helps manage EHE that’s advanced, progressing or that’s come back after surgery.

Your provider may recommend:

• Chemotherapy: Your provider may recommend chemotherapy alone or with other treatments for advanced EHE. Chemo uses drugs to destroy cancer cells. Results are mixed when it comes to how effective it is for EHE.
• Targeted therapy: This treatment uses drugs to keep tumors from getting the nutrients they need to grow. Targeted therapy treatments include small molecule inhibitors/kinase inhibitors and TEAD inhibitors. These are some of the most promising treatments being tested for EHE.

Research on epithelioid hemangioendothelioma is ongoing. And experts are constantly testing new treatments in clinical trials. Depending on your condition, your provider may recommend you take part in one.

What can I expect if I have this condition?

It’s hard to pin down a prognosis (outlook) that makes sense for everyone with EHE. A tumor may be curable if your healthcare provider removes all of it during surgery. When it’s not curable, it can be slow-growing or aggressive. It varies.

Medical experts do know the prognosis is generally better when the following apply:

• You don’t have symptoms.
• You have a small tumor (usually less than 3 centimeters, or a little over an inch) that’s only in one place.
• You don’t have lung EHE (it often involves a worse prognosis than liver EHE).

How long can you live with epithelioid hemangioendothelioma?

Very little information exists about life expectancy with EHE. First, this condition is so rare that researchers are still collecting this data. Also, the severity of EHE varies from person to person.

Several studies show that most people with EHE often survive beyond three, five and even ten years.

Still, your healthcare provider is your best resource when it comes to explaining how your diagnosis may impact your lifespan.