MCQ Detailed View

Essential Thrombocythemia (ET) is a rare chronic blood disorder in which the bone marrow produces too many platelets (thrombocytes). Unlike thrombocytopenia, where platelet numbers are low, ET is characterized by an abnormally high platelet count, often exceeding 450,000 per microliter of blood and sometimes reaching over one million.

Platelets are vital for blood clotting and preventing bleeding. However, in ET, the excessive platelet production leads to an imbalance in clotting function. Although some patients may not show symptoms in the early stages, high platelet counts can increase the risk of abnormal blood clots (thrombosis), which may block blood flow in veins or arteries. On the other hand, in some cases, platelets may not function normally, which can paradoxically cause bleeding problems.

The cause of ET is linked to mutations in bone marrow stem cells, especially in genes such as JAK2, CALR, or MPL. These mutations cause uncontrolled growth of megakaryocytes, the precursor cells that produce platelets. ET is classified as a myeloproliferative neoplasm (MPN), which means it is a blood cancer involving overproduction of blood cells.

Common symptoms of ET may include:

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  Headaches and dizziness

  
  


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  Tingling in hands or feet

  
  


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  Vision problems

  
  


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  Unexplained clotting or bleeding episodes

  
  

The severity of ET varies from patient to patient. Some individuals live normal lives with minimal issues, while others require treatment to lower platelet counts. Common treatments include aspirin (to reduce clotting risk), hydroxyurea (to suppress bone marrow activity), and in some cases, platelet-lowering therapy.

In summary, in Essential Thrombocythemia, the bone marrow produces too many platelets, leading to an increased risk of blood clotting or bleeding complications. Understanding ET provides insight into how the bone marrow regulates blood cell production and how imbalances can impact health.