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Kaposiform Hemangioendothelioma (KHE)

Last updated Oct. 22, 2018

Approved by: Krish Tangella MD, MBA, FCAP

Kaposiform Hemangioendothelioma (KHE) is an infrequent and aggressive childhood tumor, involving the blood vessels. These tumors may be located on the skin surface, or deep inside the body tissues.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Congenital Cutaneous Multifocal Kaposiform Hemangioendothelioma
  • Hemangioma with Kaposi Sarcoma-like Features
  • Kaposi-like Infantile Hemangioendothelioma

What is Kaposiform Hemangioendothelioma? (Definition/Background Information)

  • Kaposiform Hemangioendothelioma (KHE) is an infrequent and aggressive childhood tumor, involving the blood vessels. These tumors may be located on the skin surface, or deep inside the body tissues
  • KHE manifests before, or shortly after birth and is typically linked with Kasabach-Merritt phenomenon. This phenomenon is a condition, where vascular (related to blood vessels) tumors destroy blood platelets
  • KHE is commonly found in the retroperitoneum space (near abdominal cavity) and beneath the skin surface. Other locations being the head, neck, and torso
  • Any combination of steroids, chemotherapy, radiation therapy, and invasive procedures, are used to treat KHEs. However, the prognosis is based on a variety of factors. Individuals, who have other congenital type of KHE and those associated with Kasabach-Merritt phenomenon, do the worst

Who gets Kaposiform Hemangioendothelioma? (Age and Sex Distribution)

  • Kaposiform Hemangioendothelioma is generally observed in newborns. Infants may develop the condition after birth, during the initial few months
  • Some children develop the tumors, when they are very young. Adults may be affected, but this is not a regular occurrence
  • KHE seem to affect both sexes uniformly
  • There is no known ethnic or racial preference

What are the Risk Factors for Kaposiform Hemangioendothelioma? (Predisposing Factors)

The risk factors for Kaposiform Hemangioendothelioma include:

  • Presence of the potentially serious vascular condition called Kasabach-Merritt phenomenon, may indicate an undetected KHE. Kasabach-Merritt phenomenon results in decrease of platelets in blood, a condition called thrombocytopenia
  • KHE has been observed to occur with lymphangiomatosis - a rare type of congenital disorder affecting the lymphatic system

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Kaposiform Hemangioendothelioma? (Etiology)

  • Even though Kaposiform Hemangioendothelioma occurrence is congenital, there is no genetic factor involved in its formation. The exact cause and mechanism of how these tumors form, are currently being researched upon
  • It is suggested that KHE origin might be related to abnormal blood vessel proliferations, for unknown reasons during prenatal, post-natal, and early childhood phase
  • All KHEs could be life-threatening tumors, due to their capacity for platelet destruction, or infiltration into other vital organs (even though they do not metastasize to distant organs)

What are the Signs and Symptoms of Kaposiform Hemangioendothelioma?

The presentations are based on the location of the tumor. Kaposiform Hemangioendothelioma signs and symptoms include:

  • In some individuals the tumors may be asymptomatic
  • They may grow at a slow rate and appear as a painful nodular mass lesion. The tumor may also cause reduced motion range and discomfort, as they grow in size
  • Superficial KHEs might look like birthmarks - red-blue, violet colored skin surface scars, with taut skin
  • KHEs usually occur in the abdomen, causing an obstruction of the intestine. This may result in jaundice and gradual liver degeneration
  • Other locations include the neck, head, thorax, trunk, and limbs

How is Kaposiform Hemangioendothelioma Diagnosed?

A diagnosis of Kaposiform Hemangioendothelioma is made using the following tools:

  • Physical examination, evaluation of patient’s medical history
  • Blood test - this might indicate a very low platelet count (called thrombocytopenia)
  • Histopathological studies conducted on a biopsy specimen - the specimen is examined under a microscope by a pathologist, to arrive at a definitive diagnosis
  • MRI scan of the affected region: KHE in the trunk or thorax region may show bone destruction/changes

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Kaposiform Hemangioendothelioma?

Complications are dependent on the site and severity of the tumor. These include:

  • If Kasabach-Merritt phenomenon is present, then Kaposiform Hemangioendothelioma could be potentially fatal, due to platelet destruction by the tumor, leading to bleeding/clotting disorder. This complication becomes more severe, if the tumor has a congenital origin and is large in size
  • Abdominal KHEs can cause serious liver problems. The tumor nodules may damage other adjoining organs by infiltrating into them
  • The tumors can recur when they are deep-seated, even on completion of the full treatment course
  • Blood loss during invasive treatment methods may be heavy
  • Damage to vital nerves, blood vessels, and surrounding structures, during surgery
  • Side effects from chemotherapy (such as high toxicity), radiation therapy

How is Kaposiform Hemangioendothelioma Treated?

Treatment measures for Kaposiform Hemangioendothelioma include the following:

  • A combination of steroids, chemotherapy, radiation therapy, and invasive procedures, are used to treat KHEs
  • Interferon injections are used to reduce tumor blood supply, and limit its growth; after the patient is one year old
  • Vascular embolization of the tumor, by blocking the blood vessels feeding the tumor, is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
  • Wide surgical excision of KHE, with removal of the entire lesion is adopted, if necessary. If the lesion is not fully removed, then it might recur
  • If there is any pain, it is controlled through pain medications
  • Bone tumors may require the use of bone grafts
  • When KHE is at an inaccessible location, or is unsafe for surgical intervention; non-invasive procedures are adopted. This also reduces the requirement of post-surgical reconstruction and cosmetic procedures, particularly if the tumors are on the face and neck region
  • Post-operative care is important: A minimum activity level is to be ensured until the surgical wound heals
  • Follow-up care with regular screening and check-ups are important

How can Kaposiform Hemangioendothelioma be Prevented?

  • Current medical research have not established a way of preventing Kaposiform Hemangioendothelioma
  • Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations, are mandatory for those who have been diagnosed with the tumor
  • Due to both its high metastasizing potential and chances of recurrence, often several years of active follow-up vigilance is necessary

What is the Prognosis of Kaposiform Hemangioendothelioma? (Outcomes/Resolutions)

  • Kaposiform Hemangioendotheliomas are rare and not yet completely understood tumors
  • The long-term prognosis depends on a combination of factors, such as:
    • Its first appearance/detection of the tumor
    • Tumor stage
    • Tumor size and location
    • Its response to treatment and medical therapy
  • KHEs found in association with Kasabach-Merritt syndrome are potentially lethal. The outcome is particularly grim when the tumors are congenital, and located within the abdominal region
  • Surface tumors that are well-defined and can be completely excised, have a low chance of recurrence

Additional and Relevant Useful Information for Kaposiform Hemangioendothelioma:

The human herpes virus and human immunodeficiency virus have no role to play in Kaposiform Hemangioendothelioma, unlike with Kaposi sarcoma.

What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Jan. 25, 2014
Last updated: Oct. 22, 2018