Hemangioma Thrombocytopenia Syndrome: What You Need to Know
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Hemangioma Thrombocytopenia Syndrome?
This condition is usually treated by a team at a children's vascular anomalies center. The team is often led by a pediatric hematologist-oncologist, a children's doctor who treats blood problems and tumors, working with imaging, surgery, and skin specialists. Because bleeding can be dangerous, care often starts in the hospital. A pediatrician helps coordinate follow-up visits and blood tests.
What Is Hemangioma Thrombocytopenia Syndrome?
Hemangioma thrombocytopenia syndrome, often called Kasabach-Merritt phenomenon, is a rare but serious condition. It happens when a certain type of blood vessel tumor, usually a kaposiform hemangioendothelioma or tufted angioma, traps and destroys platelets. Platelets are tiny blood cells that help your blood clot, so when they drop too low, bleeding can become dangerous.
In this syndrome, a vascular tumor acts like a sponge for platelets. Platelets get stuck inside the tumor and are used up faster than the body can replace them. This causes the platelet count in the bloodstream to fall sharply, a condition called thrombocytopenia. The tumor itself is usually not a typical infantile hemangioma, but a rarer growth that behaves differently.
Who Gets It?
This condition is very rare and is seen mostly in babies and young children, though older kids can be affected in rare cases. There is no strong evidence that it runs in families. Boys and girls can both develop it.
Symptoms to Watch For
The most noticeable sign is a growing skin lesion that may look dark red, purple, or bruise-like, and it often feels firm and warm. The area may swell quickly and become painful. Low platelets can also cause small red or purple spots on the skin, easy bruising, or bleeding from the gums or nose. In serious cases, bleeding inside the body can occur and needs emergency care.
How Is It Diagnosed?
Doctors start with a physical exam and a blood test to measure the platelet count. Imaging tests such as ultrasound or MRI help show the size and depth of the tumor. Sometimes a small tissue sample, called a biopsy, is taken to confirm the exact type of vascular growth.
Treatment Options
Treatment aims to shrink the tumor and raise the platelet count. Common approaches include medicines such as sirolimus, corticosteroids, or other drugs that target the blood vessels. In some cases, compression bandages, embolization (blocking blood supply to the tumor), or surgery may be considered. Care is usually coordinated by a team of specialists, including blood doctors and vascular anomaly experts.
Living With the Condition
Most children treated early do well, though follow-up care is important for months or years. Regular blood tests and imaging help doctors track how the tumor is responding. Protecting the affected area from bumps and injuries can lower the risk of bleeding.
Common questions
Is hemangioma thrombocytopenia syndrome cancer?
No, the tumors involved are not cancer, but they can grow quickly and cause serious bleeding problems, so they need prompt treatment.
Can it go away?
With proper treatment, many children see the tumor shrink and platelet counts return to normal, though some lesions leave lasting skin changes.
Sources
- National Organization for Rare Disorders (NORD) - Thrombocytopenia Absent Radius Syndrome
- National Organization for Rare Disorders (NORD) - Cardiofaciocutaneous Syndrome
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
