Table of Contents
Definition of Thrombocythemia
A condition of the blood in which the body overproduces platelets (also called thrombocytes), resulting in dysfunctional coagulation. Thrombocythemia, also called thrombocytosis, is a myeloproliferative disorder that can be primary (an independently occurring disorder, also called essential or idiopathic thrombocythemia) or secondary (a consequence of other health conditions or splenectomy).
Doctors do not know what causes primary thrombocythemia, which occurs most commonly in people over age 50.
Common Causes of Secondary Thrombocythemia
|COMMON CAUSES OF SECONDARY THROMBOCYTHEMIA|
|Infection||Inflammatory bowel disease (IBD)|
|Iron deficiency anemia||Lymphoma|
Symptoms and Diagnostic Path
The excess platelets in the blood cause disturbances of coagulation that often result in these symptoms, which may be subtle or overt:
- Easy bleeding, notably from the mucous membranes, such as frequent nosebleeds (epistaxis), or from the gastrointestinal tract
- Easy bruising
- Clotting (thrombosis)
- Splenomegaly (enlarged spleen)
- Headache or dizziness
A blood platelet level higher than 500,000 platelets per microliter (mc/L) of blood typically confirms the diagnosis, though the doctor may choose to do a bone marrow biopsy. Bone marrow biopsy shows an abundance of megakaryocytes, the parent cells of platelets, oversize platelets, and platelet fragments.
Treatment Options and Outlook
Treatment for secondary thrombocythemia targets the underlying condition, with resolution of the thrombocythemia after improvement in that condition. Treatment for primary thrombocythemia aims to suppress myeloproliferation (bone marrow cell production activity). Common forms of myelosuppressive therapy are radioactive phosphate and the chemotherapy agents hydroxyurea and anagrelide.
Some people benefit from platelet apheresis, a form of hemapheresis that removes platelets from the blood and returns all other blood components to the person. The doctor will closely monitor the complete blood count (CBC) as well as platelet function and coagulation during treatment, usually with weekly blood tests.
Primary thrombocythemia is a chronic condition that requires ongoing treatment. Many people will remain relatively symptom-free once treatment stabilizes platelet production. The condition takes a more serious course in some people who may experience worsening symptoms, notably hemorrhage. Rarely, primary thrombocythemia evolves into chronic myeloid leukemia (CML), a cancer of the bone marrow.
Risk Factors and Preventive Measures
Because doctors do not know what causes primary thrombocythemia, risk factors remain unknown and there are no known preventive measures. Early diagnosis and appropriate treatment offer the most optimal prognosis (outlook) to minimize the level to which the condition affects quality of life.