What Is Epithelioid Hemangioendothelioma? Symptoms, Treatment and Disease Course

Other known names

• Adult Epithelioid Hemangioendothelioma 
• Intravascular Bronchioloalveolar Tumor 
• Low Grade Anaplastic Angiosarcoma

What is hemangioendothelioma? 

Hemangioendothelioma is a vascular tumor of soft tissue.

Hemangioendothelioma is a term describing various vascular neoplasms (blood vessel tumors), including both noncancerous and cancerous (malignant) growths. It is one of the rare tumors. The term is also used for tumors showing "borderline" behavior between benign hemangiomas and aggressive malignant angiosarcomas . Although the exact cause of abnormal growth in hemangioendotheliomas is unknown, it results from abnormal growth of blood vessel cells. They tend to occur in soft tissues beneath the skin or in organs such as the liver or lungs. They generally grow slowly and may sometimes spread to other tissues in the body (metastasis). Examples include spindle cell hemangioma; papillary intralymphatic (Dabska tumor); retiform; kaposiform; epithelioid; pseudomyogenic (epithelioid sarcoma-like hemangioendothelioma); and composite types. Treatment depends on the type present but typically involves surgical excision (removal by surgery). 

Hemangioendothelioma is a tumor involving blood vessels and surrounding epithelioid cells, and is therefore often called Epithelioid Hemangioendothelioma (EHE) . Blood vessels are lined with epithelioid cells that grow abnormally to form the tumor.

Most of these tumors behave benignly; however, they have malignant potential (capacity to metastasize). 

Epithelioid hemangioendothelioma represents 1% of all vascular tumors and is therefore very rare. It may appear as a single mass or multiple masses.

EHE often affects soft tissues just beneath the skin (subcutaneous tissue). It may also develop deep within body organs.

This tumor has been observed in the liver, lungs, legs, bones (vascular tumor of bone) and skin. Although adolescents and young adults are most often affected, it can occur in any age group.

A person may experience a painful mass and tenderness due to the tumor. Some are asymptomatic, causing no obvious signs or symptoms (complaints).

Who is most often affected by epithelioid hemangioendothelioma?

• Epithelioid hemangioendothelioma can occur at any age. It is most common among adolescents and young adults.
• Infants and very young children are rarely affected.
• EHE affects both sexes (men and women) equally.
• It has no preference for any ethnic group or particular race.

What are the risk factors for epithelioid hemangioendothelioma?

• Any developmental tissue abnormality involving soft tissues may be a risk factor.
• Epithelioid hemangioendothelioma of the liver has been associated with oral contraceptives .
• Having a risk factor does not mean a person will necessarily develop the associated disease. A risk factor increases the likelihood compared with an individual without risk factors. Some risk factors are more important than others. Conversely, not having a risk factor does not mean you will not develop the condition. It is always important to discuss their effects on your health with your physician.

What are the symptoms of epithelioid hemangioendothelioma?

The signs and symptoms of this rare tumor depend on its location.

• Most tumors are asymptomatic (cause no signs, findings or complaints); symptomatic tumors, however, show a broad range of behavior.
• They may grow slowly and appear as painless, irregular/lumpy masses beneath the skin (subcutaneous). They may also occur as deep-seated tumors.
• They may appear as well-defined single or multiple nodules at different sites. If these nodules lie beneath the skin, changes in skin color (red-brown or pink) may be noticeable.
• They behave aggressively locally and may damage surrounding tissues.
• EHE is most commonly found in the liver, lungs, bones, feet and skin.

How is epithelioid hemangioendothelioma diagnosed?

The following tools are used to diagnose epithelioid hemangioendothelioma:

• A comprehensive assessment of medical history and a complete physical examination.
• X-ray (plain radiograph) studies of the affected area: however, plain radiographs generally make it difficult to distinguish between other hemangiomas, such as telangiectatic osteosarcoma, aneurysmal bone cyst, fibrous dysplasia, etc.
• Computed tomography and MRI scans of the affected area. MRI is the radiological examination that best shows soft tissues. 
• Tissue biopsy of the tumor: a biopsy is performed and sent to a laboratory for pathological examination. A pathologist examines it under a microscope. After combining clinical findings, special tissue studies (if needed) and microscopic findings, the pathologist reaches a definitive diagnosis. Microscopic examination of a biopsy by a pathologist is considered the gold standard for definitive diagnosis.

What are the possible complications (problems caused) of epithelioid hemangioendothelioma?

Complications depend on the site and severity of the tumor. They include:

• Liver degeneration (damage), paraplegia (spinal cord paralysis), fused vertebral bones due to a damaged spinal cord.
• Recurrence of epithelioid hemangioendothelioma after surgery.
• Blood loss during surgery and other invasive treatments may be severe; blood may accumulate outside vessels, causing hematomas.
• Severe pain if internal organs are affected.
• Removal of all or part of a limb (amputation).
• Vital nerves, blood vessels and surrounding structures may be damaged during surgery.
• Side effects of chemotherapy or radiotherapy (such as toxicity).

How is epithelioid hemangioendothelioma treated?

• Wide surgical excision (removal by surgery) is the mainstay of treatment. The lesion may recur if not completely removed.
• Embolization (angiographic blockage of vessels feeding the tumor) may be used to provide temporary symptom relief and reduce blood loss during surgery.
• Aggressive lesions may require critical treatment: bone tumors may require bone grafts; amputation may be recommended for limb lesions. Liver tumors may require liver transplantation.
• When EHE is inaccessible or unsafe for surgical intervention, radiation therapy, chemotherapy, interferon injections and other oral chemotherapy drugs are used.
• Postoperative care is important: activity should be kept to a minimum until the surgical wound heals.
• Follow-up care with regular screening and checks is important.

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What is the prognosis of epithelioid hemangioendothelioma? (Disease course and outcomes)

• Epithelioid hemangioendothelioma is a very rare tumor with metastatic / malignant potential. Metastatic tumors may cause death; mortality in aggressive EHE is between 10-20%.
• Long-term prognosis (disease course and outcomes) depends on a combination of factors such as the tumor's initial appearance/detection, size and location, response to treatment and medical therapy.
• Some tumors are self-limited, asymptomatic and may not require any treatment; they may regress completely.
• Prognosis is generally good when lesions are small and located beneath the skin's surface.
• After surgical removal, the likelihood of EHE recurrence is moderate, at 10-15%. Regular follow-up is therefore necessary.
• Despite all treatment measures, some epithelioid hemangioendotheliomas may metastasize, causing multiple organ dysfunction syndrome (MODS).

The following factors make epithelioid hemangioendothelioma difficult to manage:

• The tumor's extreme rarity
• Its variable behavior
• Its potential to affect various body regions and organs
• The lack of standard treatment guidelines in the medical literature on epithelioid hemangioendothelioma

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