Understanding Epithelioid Hemangioendothelioma: A Rare Vascular Cancer

Dr. Michael Wagner covers the basics of epithelioid hemangioendothelioma, a rare vascular cancer, spanning symptoms, diagnosis, treatment options and more.

Epithelioid hemangioendothelioma (EHE), a very rare type of vascular cancer, is diagnosed in approximately one in 1 million people. Because it's so uncommon, many individuals, including some oncologists, haven't heard of it.

“There is only about 150 people in the whole country who are diagnosed with it, and because it's a tumor of the blood vessels, it can [arise] basically anywhere in the body, and the behavior of them can be actually quite variable,” Dr. Michael J. Wagner said in an interview with CURE.

Wagner is a clinical research director and senior physician at Dana-Farber Cancer Institute, and faculty member at Harvard Medical School, both in Boston, Massachusetts,

In the interview, Wagner defines EHE and how it can show up in the body, as well as symptoms and the variability of prognostic indicators for this patient population.

CURE: At the basic level, what is EHE?

Wagner: EHE is short for epithelioid hemangioendothelioma, which is a mouthful, so that's why I call it EHE. It is a very rare vascular tumor. Tumors, or in some cases, cancers, can develop from the blood vessels, and specifically the inner lining of the blood vessels, which is called the endothelium. Those can be anywhere from benign hemangiomas, which are quite common, to what we consider most aggressive vascular sarcoma, which is an angiosarcoma.

Then, there is this group of diseases in the middle that are various hemangioendotheliomas, and EHE is the most common of those, but it's still very rare. Some people will have EHE tumors that are just there and, in many cases, found even incidentally. Others have EHE that tends to behave more aggressively, and we would treat those just like any other cancers.

EHE is a growth that is abnormal of the blood vessels that we generally would consider a tumor, and they are usually characterized by abnormal changes in the chromosome. Sometimes one piece of a chromosome can be put next to another, and with EHE, there are some very specific chromosomal changes that we'll see, and that's what helps make the diagnosis.

What symptoms does a patient with EHE present with?

That is one of the difficult things about EHE. Because it can come up anywhere, almost any sort of symptom, in theory, could be caused by it and a lot depends on where the tumor is. Sometimes these will come up in the liver; it's one of the more common places that we'll see them, and it might just be incidentally found on a scan that's done for something completely unrelated. If someone goes into the emergency room and gets a scan of their abdomen, for example, for some abdominal pain, sometimes something will just appear on the liver, and the radiologists will call it out.

Pain is one of the more common, if not the most common symptom that people will experience from an EHE, and it's just the workup of trying to figure out the cause of the pain.

Are there any kind of genetic or environmental risk factors that can be associated with an EHE diagnosis?

As far as we know, it's random. It's not something that we consider hereditary, and there aren't any clearly known exposures or anything like that that increases someone's risk of developing an EHE.

How common is it for EHE to be misdiagnosed? What can EHE be misdiagnosed for?

That is an excellent question that raises an important point, where the short answer is: EHE and even more broadly, many sarcomas, EHEs can often be misdiagnosed. It is such a rare tumor that most pathologists don't have much experience looking at EHE under the microscope. Someone might present with what looks like metastatic disease or a new mass, get a biopsy, and it can sometimes be either diagnosed as a different type of vascular tumor.

For example, I have seen angiosarcoma on a pathology diagnosis that then turns out to be EHE. Sometimes even carcinomas of some of the more common types of cancers can be mimicked by EHE, just based on the way it looks under the microscope. If EHE is being considered in the diagnosis. it's important that the specimen be looked at by a trained and experienced sarcoma pathologist to help differentiate all the various possibilities.

What is the prognosis for someone with EHE? What disease characteristics factor into what their disease journey will look like?

One of the unusual things about EHE is that sometimes even with metastatic disease, the tumors can just sit there and not really grow and not necessarily be causing any symptoms. I have many patients who I'm following who have bilateral lung metastases, for example, and sometimes even multiple spots in their liver, and they're not on any treatment, and we're just watching them. For most patients, one of the first steps we'll take is to get a scan in a few months, and if they're clinically the same, we just see what that next scan looks like. For many of those patients, we'll see no growth from one scan to the next roughly three or so months later. If they're doing well, then we'll just keep watching it.

There are a few things that would suggest a worse prognosis, and I would say the biggest of those is the presence of ascites or pleural effusions. For patients who do develop what we call serosal effusions, or fluid around the lung or in the belly that is being produced by the tumors, that suggests that it's behaving much more aggressively, and we would want to start some sort of systemic treatment sooner rather than later.

If it does look like there's growth from one scan to another, or someone has worsening pain, then we would want to treat, ideally, before it gets to the point where there's fluid like that because that becomes more difficult to treat.

How long can someone live with EHE?

It can vary quite a bit. Although there are some data about what the median survival is, some patients will have disease that seems to be growing more quickly, and others will live for years and years with metastatic disease; [for them] we might have to treat intermittently or do some more focused treatment. There are people with metastatic disease who can live for many years. The median is somewhere on the order of several years, [but in looking back at earlier data] there's a very long tail in that curve. Roughly 40%. or so of patients will live long-term, almost normal lives.

Transcript has been edited for clarity and conciseness

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