Thrombocytosis is a blood disorder, in which the body produces a surplus of platelets (thrombocytes). Platelets are blood cells that stick together, helping blood clot. The cause of essential thrombocytosis is unknown. Secondary thrombocytosis may have many causes, including acute hemorrhage, anemia, arthritis, classify term="cancer" project="woh" type="bookxref">cancer, and certainmedications. Surgery, particularly removal of the spleen (splenectomy), mayalso be a causative factor.
Two of every three patients who have thrombocytosis do not have any symptomsof the disease at the time of diagnosis. Younger patients may remain symptom-free for years. Enlargement of the spleen is detected in 60% of patients withthrombocytosis. The liver may also be enlarged. As many as half of all patients experience bleeding from the skin, gums, or nose, and 20-50% have some blockage of veins or arteries.
Other symptoms of thrombocytosis include:
- Bloody stools
- Prolonged bleeding after having surgery or after having a tooth pulled
- Redness or tingling of the hands and feet
- Weakness. In rare instances, the lymph nodes become enlarged.
The highest platelet counts usually produce the most severe symptoms. Youngerpatients (especially women) may not have symptoms, even though their platelet counts are very high. Complications of thrombocytosis include stroke, heartattack, and formation of blood clots in the arms and legs.
A doctor should be notified whenever bleeding is unexplained or prolonged orthe patient develops:
- Chest or leg pain
Any patient who has thrombocytosis should be encouraged not to smoke. In young people who have no symptoms, this condition can remain stable for many years. These patients should be monitored by a physician, but may not require treatment. Treatment for patients who do have symptoms focuses on controlling bleeding, preventing the formation of blood clots, and lowering platelet levels. Treatment for secondary thrombocytosis involves treating the condition or disease responsible for excess platelet production.
In 1997, the United States Food and Drug Administration (FDA) approved the use of anagrelide HCI (Agrylin) to reduce elevated platelet counts and decreasethe risk of clot formation. Some patients have benefited from the use of hydroxyurea, an anti-cancer drug. Low doses of aspirin may prevent clotting, butcan cause serious hemorrhages. If drug therapy does not bring platelet counts down to an acceptable level as rapidly as necessary, plateletpheresis may be performed. Usually combined with drug therapy and used primarily in medicalemergencies, this procedure consists of:
- Withdrawing blood from the patient's body
- Removing platelets from the blood
- Returning the platelet-depleted blood to the patient.
Many patients with thrombocytosis remain free of complications for long periods. However, some patients may die as a result of blood clots or uncontrolledbleeding. There is no known way to prevent thrombocytosis.