Information on the following diseases can be found in the Related Disorders section of this report:

• Blue Rubber Bleb Nevus
• Cavernous Hemangioma
• Thrombocytopenia, Essential

Hemangioma-Thrombocytopenia Syndrome is a rare disorder that is typically characterized by a benign (non-cancerous) tumor consisting of large, blood- filled spaces (cavernous hemangioma). This tumor occurs along with a blood condition (thrombocytopenia) characterized by an abnormally low number of blood platelets which can cause excessive bleeding.

Excessive bleeding (hemorrhaging) beneath the skin (purpura) typically develops within the first six weeks of life, but may appear later in childhood as the hemangioma increases in size. Usually there is only one hemangioma which is found on the neck, arms, legs, or trunk of the body. Less common are tumors of the internal organs which may be found on the tongue, thorax, spleen, liver, gastrointestinal tract or bones. Hemangiomas are rarely found internally and on the skin of the same patient.

Thrombocytopenia may occur within the first month of life in association with a hemangioma of the outer layer of the placenta (placental chorioangioma) or large hemangiomas of the skin.

Hemangiomas may become filled with blood (engorged) before a bleeding spell occurs. The cause of the bleeding is not certain, but it can be triggered by trauma.

A decrease in the level of the oxygen carrying component of blood cells (hemoglobin), red blood cells (erythrocytes), and/or proteins in the blood that are part of the clotting process (prothrombin and fibrinogen) may also occur. However, fibrinogen deficiency usually affects older children and adults.

The exact cause of Hemangioma-Thrombocytopenia Syndrome is not known. It is thought that the thrombocytopenia may be a result of platelet destruction which occurs in relationship to growth of the hemangioma. There is no evidence that the syndrome is hereditary.

Hemangioma-Thrombocytopenia Syndrome is a very rare disorder that affects males and females in equal numbers. Approximately one in every five hundred cases of people with hemangiomas have associated thrombocytopenia.

Symptoms of the following disorders can be similar to those of Hemangioma- Thrombocytopenia Syndrome. Comparisons may be useful for a differential diagnosis:

Blue Rubber Bleb Nevus is characterized by soft, elevated, blue, blue- black or purplish-red swellings, called hemangiomas or nevus, on the skin or just under the skin. The nodules may be tender, contain blood and be easily compressed. External nevi are usually located on the upper arms or trunk. Internally, nevi may be located in many different sites such as the liver, lungs, spleen, gallbladder, kidney and skeletal muscles. Serious complications may accompany internal growths. When the gastrointestinal tract is affected, uncontrolled bleeding may result in chronic anemia. If nevi are located in the brain, they may cause bleeding and increased intracranial pressure. (For more information on this disorder choose "Blue Rubber Bleb Nevus" as your search term in the Rare Disease Database.)

Cavernous Hemangioma is a rare, often congenital, disorder of the venous (veins and arteries) system. The hemangioma is a mass resembling a tumor, consisting of large blood-filled spaces that may occur at any site in the body. This disorder may be either acquired or inherited as an autosomal dominant genetic trait. Cavernous Hemangioma may be found alone or in association with other syndromes. (For more information on this disorder, choose "Cavernous Hemangioma" as your search term in the Rare Disease Database.)

Essential Thrombocytopenia is a rare blood disease affecting the platelets of the blood. This causes clotting abnormalities. It is characterized by an abnormally low platelet count and a shorter than normal (ten days) platelet survival time. Major symptoms include a tendency to bleed excessively into the skin or mucous membranes, especially during menstruation. There are many different reasons for the decreased marrow production and platelet destruction that causes this disorder. (For more information on this disorder, choose "Essential Thrombocytopenia" as your search term in the Rare Disease Database.)

Cavernous hemangiomas can be diagnosed with the use of various diagnostic imaging methods such as: Magnetic Resonance Imaging (MRI), Computed Tomography (CT) Scans, and X-Rays. This provides a comprehensive picture of the hemangioma and gives the doctor an understanding of the treatment options.

Hemangiomas may disappear for no apparent reason (spontaneously) in some people affected with Hemangioma-Thrombocytopenia Syndrome.

Treatment may become necessary when the hemangioma grows large or severe hemorrhaging occurs. Surface hemangiomas may be surgically removed followed by immediate correction of the blood abnormalities. When the hemangioma is inoperable, or there are multiple hemangiomas, radiation may be required. Platelet transfusion may be necessary to help coagulate the blood when hemorrhaging occurs. Laser surgery may be beneficial in removing the hemangiomas in some cases.

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

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