Myeloproliferative neoplasms (MPNs) are a category of hematologic malignancies characterized by clonal proliferation of myeloid cells, leading to an overproduction of mature blood cells. They arise from mutations in hematopoietic stem cells, with the most common mutations occurring in the JAK2, CALR, and MPL genes. These mutations lead to constitutive activation of the JAK-STAT signaling pathway, promoting unchecked cell proliferation. MPNs are broadly classified into "classic" types: - **[[Polycythemia Vera]] (PV):** Increased production of red blood cells, often accompanied by elevated levels of white blood cells and platelets. - [[Essential Thrombocythemia]] (ET):** Primarily an overproduction of platelets, leading to thrombotic events. - [[Primary Myelofibrosis (PMF)]] (PMF):** Characterized by bone marrow fibrosis, leading to anemia and splenomegaly as the spleen and liver take over blood cell production. The clinical presentation of MPNs can vary widely, from asymptomatic in early stages to symptoms related to blood hyperviscosity, increased risk of thrombosis, or effects of enlarged spleen. Diagnosis involves blood tests, bone marrow biopsy, and genetic testing for specific mutations. Treatment strategies for MPNs focus on managing symptoms, reducing the risk of complications such as thrombosis, and in some cases, targeting the underlying genetic abnormalities. Therapeutic options include phlebotomy (for PV), cytoreductive therapy, low-dose aspirin (for ET), and JAK2 inhibitors. The choice of treatment depends on the specific type of MPN, the patient's risk factors for complications, and the presence of symptoms.