If your child has been diagnosed with kaposiform hemangioendothelioma (KHE), you probably have many questions:
- What is it?
- Will it go away?
- How is it treated?
- What does it mean for my child?
We’ve tried to provide some answers to these questions in these pages, and when you meet with our experts, we can further explain your child’s condition and treatment options.
Is my child’s lesion painful?
Often yes, but not in all cases. As the tumor gets bigger and more aggressive, a lesion can swell and may be very painful. This may also occur with infection, trauma to the lesion or after platelet transfusion.
Does KHE always lead to Kasabach-Merritt phenomenon?
Not always, although nearly 75 percent of cases referred to us here at Children’s Hospital Boston have or develop Kasabach-Merritt phenomenon.
KHE lesions that are larger and invade into deeper tissues are more likely to trap platelets and have bleeding risk. In very rare situations, KHE can involve only your child’s bones and occasional superficial lesions; these appear to have low risk of Kasabach-Merritt phenomenon.
How common is it?
It’s very rare, representing less than 1 percent of birthmarks. The incidence is unknown, but is likely less than 1 in 100,000.
Children’s Vascular Anomalies Center has the largest database in the world of information describing KHE cases — it includes more than 160 cases (as of 2010).
What does a KHE lesion look like?
KHE may have the following characteristics:
- It’s usually a deep, reddish-purple.
- It is firm and warm to the touch.
- The skin is often shiny and tense.
- There may be tiny purple or red spots and a bruise-like discoloration near or around the lesion.
- About 10 percent of kids with KHE have no skin lesion and some lesions penetrate deeper than the skin into other tissues.
Where does the lesion appear?
It can appear anywhere on your child’s body. It is often found on the head and neck, but can also appear on the stomach, back, arms and legs — even inside the chest, abdomen or bones.
What causes Kaposiform hemangioendothelioma?
KHE is not inherited — researchers are still studying the cause of these rare tumors. Abnormal blood vessel formation and growth typically occurs in infancy, although it can happen prenatally and also in adults after trauma.
Signs and symptoms
What are the symptoms of KHE?
Often, KHE can be misdiagnosed by your child’s primary physician, simply because the condition is so rare. Here are some signs that you can look for; if your child has one or more of these symptoms, we recommend getting a second opinion from a vascular anomalies specialist.
- a lesion on the skin that’s getting larger than expected
- a lesion that swells and becomes painful
- pain with movement or decreased range of motion around the area of the lesion
- low platelet count
KHE may also show up with different symptoms based on the location of the lesion.
What is the long-term outlook for my child?
KHE is such a rare tumor that it’s difficult to determine the long-term outlook for your child, though we are actively researching this question. Every child is unique and your care team will work with you to develop a treatment plan that works for your family. We will openly share our experience about outlook and prognosis with you.
It’s important to get prompt medical attention when KHE is suspected to allow early discussions about treatment. This enables your doctor to attempt to shrink the tumor before it affects adjacent muscle or tissue — early treatment could also help lessen long-term complications by preventing further growth.
The prognosis for your child depends on:
- the extent of the disease
- the size and location of the tumor
- the tumor's initial response to therapy
- new developments in treatment
Will my child’s tumor come back after treatment?
There is some evidence that these tumors can recur, though it is currently unclear how common this is. However, if your child’s tumor does recur, we have good success treating it again, reducing its size and stabilizing your child’s platelet count.
What do we do after treatment is over?
Your child should continue with regular, thorough clinic visits at least every year. The purpose of these visits is to monitor for recurrence and rare late effects from therapy.
A typical follow-up visit may include some or all of the following:
- a physical exam
- blood tests
- imaging or scans
Q: Is kaposiform hemangioendothelioma a birthmark?
A: No. KHE is a vascular tumor that causes a discolored lesion or birthmark on your child’s skin.
Q: Is KHE a hemangioma?
A: No. Hemangiomas have a different appearance, grow predictably and shrink and fade on their own. They also look different when biopsied. KHE is not associated with infantile hemangiomas, although KHE is sometimes misdiagnosed as a hemangioma.
Q: Does my child have cancer?
A: No. We use the term “tumor” to mean any abnormal growth. While we refer to KHE as a tumor, it’s a benign tumor, which means it doesn't metastasize and spread to other locations in your child’s body.
Q: If it’s not cancer, why is it a problem?
A: KHE is a problem because the tumor can affect adjacent muscle or tissue. This can result in three different kinds of problems:
- pain/difficulty moving — If the tumor spreads into adjacent muscle tissue, your child may have difficulty moving the affected area (such as an arm or a leg). There may also be pain involved.
- damage to an internal organ — If the tumor spreads too close to an internal organ, it can hurt that organ.
- bleeding — As the tumor grows, it captures more platelets, putting your child at risk for bleeding. This is referred to as Kasabach-Merritt phenomenon.
Q: Is KHE treatable?
A: Yes, although treatment is not always necessary.
- Our doctors use different medications to stop the growth of the tumor, improve your child’s platelet count and help prevent any complications.
Q: What kinds of medications are used?
A: Our doctors will often recommend steroids first and then move on to chemotherapy or interferon therapy if steroids are not effective.
For detailed information on all aspects of treatment, see the Treatment & Care section.
Q: What makes Children’s different?
A: We’re home to the largest Vascular Anomalies Center in the world. We assist doctors in other states or other countries with diagnosis and treatment of vascular anomalies like KHE, evaluating about 1,000 cases of vascular anomalies annually. We have more experience evaluating, diagnosing and treating children with KHE than any other hospital in the world.
Q: My child has a low platelet count and a birthmark that was diagnosed as a hemangioma. Should I get a second opinion?
A: Yes. If your child’s platelet count is low and he has a vascular tumor or birthmark, you should definitely consult a vascular anomalies center.
A low platelet count is never caused by common infantile hemangioma. Low platelets combined with a skin lesion should lead to evaluation for KHE or other benign vascular tumors like tufted angioma or cutaneovisceral angiomatosis with thrombocytopenia (CAT) — also called multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT).
Keep in mind, however, that KHE is very rare and having these two symptoms doesn’t necessarily mean that your child has a vascular tumor. There are other reasons your child may have low platelets and our experts can clarify the cause in your child.
Q: My child has a low platelet count and our doctor recommended a transfusion. Now the lesion is bigger than ever and more painful. What happened?
A: What happens in a platelet transfusion is that all the new platelets are quickly attracted to the tumor and trapped. Your child’s lesion will quickly grow and become extremely painful. Over time, it will shrink back to its normal size over time, but your child’s platelet count will not improve from the transfusion. We only recommend a platelet transfusion if your child is bleeding badly — not simply because a platelet count is low.
It’s important to treat the tumor, not the platelet count. Your child’s platelet count will go up as the tumor shrinks (because it’s not trapping as many platelets). We focus on shrinking the tumor, understanding that the platelet count will normalize as your child’s tumor becomes less aggressive.
Questions to ask your child’s doctor
After your child is diagnosed with KHE, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you.
Lots of parents find it helpful to jot down questions as they arise – that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed.
If your child is old enough, you may want to suggest that she write down what she wants to ask her health care provider, too.
Some of the questions you may want to ask include:
- How will my child’s KHE be treated?
- Will my child need to stay in the hospital?
- What side effects or complications might my child experience due to treatment?
- What kind of follow-up care should my child receive? How often will she need to come in?
- How much experience does this center and my child’s doctor have with treating KHE?
Keep family and friends up to date during your child’s treatment by creating a free Children’s CarePage.
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