To view this article in the new Rare Cancers Australia Knowledgebase, click here
Epithelioid hemangioendothelioma (EHE) is a rare vascular (endothelial cell) sarcoma that is composed of mostly round (epithelioid) cells that can arise in soft tissue, bone, and organs such as liver and lung. Benign endothelial cell neoplasms (hemangiomas) are very common while malignant endothelial cell cancers (hemangioendotheliomas and angiosarcomas) are very rare. EHE may arise as a solitary lesion but more commonly presents with metastatic (widespread) involvement, typically involving the liver and lung with numerous small tumor nodules. 61% of liver EHE present with metastatic disease. Disease-specific mortality has been estimated around 13-18% for EHE arising in soft tissue, while the disease-specific mortality rate for EHE in the lung and liver is 40% and 65% respectively.1 Although localized (single lesion) EHE can be resected, there is no reliable medical treatment for metastatic (widespread) EHE, underscoring the need to develop targeted therapy.
EHE is a difficult diagnosis histologically and can be confused with carcinoma and other epithelioid vascular neoplasms. Since as a group, the prognosis of epithelioid vascular tumors vary greatly, from benign lesions such as epithelioid hemangioma without any metastatic potential, to very aggressive cancers such as epithelioid angiosarcoma, it is important to classify these lesions precisely.
How do doctors diagnose EHE?
Diagnosing EHE is a process that happens in a few stages because the skin lesions associated with EHE are often confused with more common skin conditions:
- Your doctor will evaluate any internal lesions based on the symptoms caused by the locations of EHE tumor(s).
- Your doctor may recommend an imaging study based on physical signs or results from blood tests.
- An experienced radiologist may consider EHE based on imaging.
- Tumors seen on imaging are often biopsied and a pathologist may be the first person to consider the diagnosis of EHE.
- Biopsy is nearly always needed to confirm the diagnosis of EHE.
Referring to EHE as a rare tumor often leads to discussion of EHE as a cancer. A tumor is any abnormal growth, while cancer has additional properties, including spreading to distant parts of the body and rapid growth. In some patients, the tumor is stable and sometimes goes away without treatment. In others, the tumor may be more aggressive, metastatic (meaning that it can spread) and can even be fatal.
As is the case for all rare diseases, it is recommended that an experienced team of specialists assist in ensuring your child has the correct diagnosis.
Adamantinoma of the long bones, or extragnathic adamantinoma, is an extremely rare, low-grade malignant tumor of epithelial origin. It is not related to adamantinoma or ameloblastoma of the mandible and maxilla which is derived from Rathke's pouch. Adamantinoma is a locally aggressive osteolytic tumor
There is often a history of trauma associated with adamantinoma but its role in the development of this lesion remains unclear. The patient usually has swelling that may be painful. The duration of symptoms can vary from a few weeks to years.
Here’s what you need to know:
- EHE is a rare vascular tumor that arises from the lining of your child’s blood vessels.
- It can appear anywhere in the body, but common sites are the liver, lungs and bones.
- The cause is currently unknown.
- The tumor behaves differently in different people.
- Some are stable for years.
- Some go away without treatment.
- Some grow rapidly, spread and can even be fatal.
- There are several treatments available for epithelioid hemangioendothelioma.
What are the treatment options?
EHE is a complex condition. Your care team will outline the benefits of all the treatment options listed below with you.
If there are no obvious complications, your child's doctor may want to simply observe the tumor for a period of time.
Observation allows your child's care team to determine how the tumor is behaving.
For example, some tumors go away without treatment, so if your doctors observe the tumor for a few months and see that it's shrinking, it probably won't be recommend any treatment. This is an important option to avoid unnecessary treatment.
However, if it is observed growing, doctors can immediately step in with aggressive treatment to stabilize, shrink or remove the tumor.
If your child's tumor is small and/or in an easily accessible spot, your doctor will probably recommend surgery to remove it.
If your doctor thinks it's impossible to remove the whole tumor surgically—or if there are multiple tumors in several locations—It'll probably be recommended that one of several medications are used to slow the growth of the tumor by interfering with abnormal cell growth.
Some of these medications are targeted to blood vessel formation (anti-angiogenic) and others target cell division and growth (chemotherapy). Medications may be used in combination and sometimes the first regimen isn't successful and others may be recommended. Unfortunately, there is no current drug that specifically targets the abnormal EHE cells.
These medications need to be given and monitored by an experienced hematology/oncology team.
For more information on Epithelioid hemangioendothelioma, click here or alternatively here. Information has also been sourced from cancerresearchuk.org
For more technical information, please follow the links below.
http://rca.blob.core.windows.net/assets/uploads/files/02_Flucke et al_2014_Diagnostic Pathology.pdf
http://rca.blob.core.windows.net/assets/uploads/files/03_Ravi_2013_Current Oncology Reports.pdf
For information about clinical trials that are available in Australia click here