From the Research
Chronic thrombocytosis in your patient is most likely due to essential thrombocythemia, a myeloproliferative neoplasm characterized by excessive platelet production, which can increase the risk of thrombosis and bleeding, as supported by the most recent study 1. To determine the specific cause of thrombocytosis, a complete blood count with peripheral smear, iron studies, inflammatory markers (ESR, CRP), and JAK2, CALR, and MPL mutation testing are recommended. The differential diagnosis includes myeloproliferative neoplasms (polycythemia vera, primary myelofibrosis, chronic myeloid leukemia); inflammatory conditions such as rheumatoid arthritis and systemic lupus erythematosus; infections; splenectomy; iron deficiency anemia; and solid tumors such as lung cancer. Approximately 90% of individuals with essential thrombocythemia have genetic variants that upregulate the JAK-STAT signaling pathway, including Janus kinase 2 (JAK2, 64%), calreticulin (CALR, 23%), and myeloproliferative leukemia virus oncogene (MPL, 4%) 1. If myeloproliferative neoplasm is confirmed, treatment may include low-dose aspirin (81-100 mg daily) to prevent thrombotic events, and cytoreductive therapy such as hydroxyurea (starting at 500-1000 mg daily) for high-risk patients, as suggested by the study 2. Management should be tailored to the underlying cause - treating the primary condition for reactive thrombocytosis or implementing specific therapy for myeloproliferative disorders. Key factors to consider in the management of essential thrombocythemia include the patient's age, history of thrombosis, and the presence of cardiovascular risk factors, as well as the results of genetic testing for JAK2, CALR, and MPL mutations 3. The distinction between reactive and clonal thrombocytosis is crucial as it determines treatment approach and prognosis, with clonal disorders generally requiring hematology referral for specialized management. In terms of prognosis, the median overall survival for patients with essential thrombocythemia exceeds 35 years in those diagnosed at 40 years or younger, but the risk of thrombosis and bleeding complications remains a concern throughout the patient's life, as noted in the study 1. Overall, a comprehensive diagnostic evaluation and individualized treatment approach are essential to optimize outcomes for patients with chronic thrombocytosis due to essential thrombocythemia.