American Board of Internal Medicine (ABIM) Certification Practice Exam

Who should be treated for essential thrombocythemia?

1. Patients under 50 years of age

2. Patients with a platelet count below 500,000/µL

3. Patients older than 60 years

4. Patients with no history of thrombosis

The correct answer is: Patients older than 60 years

Treatment for essential thrombocythemia (ET) is primarily indicated for patients who have a higher risk of thrombotic events, which tends to be associated with age and certain clinical features. In this case, the correct choice is patients older than 60 years. This age group is critical because the risk of complications associated with ET, such as thrombosis, significantly increases with age. Therefore, treating older patients is a strategy to mitigate these risks. In individuals over 60, the likelihood of developing cardiovascular events or cerebrovascular incidents is heightened, making them prime candidates for therapy aimed at lowering platelet counts and reducing thrombotic risks. Other factors considered when determining treatment in patients with ET include history of thrombosis, high platelet counts (typically over 1,000,000/µL), and the presence of symptoms. However, the most straightforward and universally accepted guideline is based on age, with individuals over 60 considered for treatment even if they do not exhibit other high-risk features. Patients under 50 years of age and those with lower platelet counts or no history of thrombotic events may not require immediate treatment, as the risks for severe complications are lower in these populations.