At a Glance Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm (CMPN) characterized by a clonal proliferation of megakaryocytes that typically leads to a marked thrombocytosis. Approximately one-half of patients are asymptomatic at diagnosis, whereas the other half presents with thrombosis or bleeding. Of note, many chronic myeloproliferative neoplasia (CMPN) may present with thrombocytosis, and…
At a Glance Polycythemia vera (PV) is a chronic myeloproliferative disorder characterized by a proliferation of megakaryocytes, granulocytes, and erythrocytes in the bone marrow, leading to thrombocytosis, leukocytosis, and erythrocytosis in the peripheral blood. Patients are often asymptomatic, and it is detected only when routine blood work shows increased hematocrit or hemoglobin. If symptomatic, patients…
At a Glance Myelodysplastic syndrome (MDS) is a group of diseases that are due to ineffective hematopoiesis. The primary clinical findings in these patients are related to the sequelae of cytopenias (i.e., fatigue/dyspnea, bruising/bleeding, and infections). The primary morphologic finding is that of dysplasia in a cytopenic patient and, typically, a hypercellular bone marrow. Because…
At a Glance Chronic Eosinophilic Leukemia (CEL) is a chronic myeloproliferative neoplasm (CMPN) characterized by a clonal proliferation of eosinophilic precursors that leads to increased eosinophilia in the peripheral blood, the bone marrow and possibly peripheral tissues. Patients can present with fever, fatigue, cough, diarrhea, myalgias, pruritus, or angioedema reflecting activation and degranulation of the…
At a Glance Primary myelofibrosis (PMF) is a chronic myeloproliferative neoplasm (CMPN) characterized by a clonal proliferation of granulocytes and megakaryocytes and a propensity to develop marked fibrosis of the bone marrow. At early stages, patients present with leukocytosis and/or thrombocytosis, but most cases typically proceed to pancytopenia or even acute myeloid leukemia in 5-30%…
At a Glance Chronic Neutrophilic Leukemia (CNL) is a vanishingly rare disease (less than 1% of chronic myeloproliferative neoplasia (CMPN)) characterized by a persistent leukocytosis greater than 25,000/μl comprised of more than 80% segmented neutrophils and bands. There must be less than 10% immature myeloids and less than 1% myeloblasts in the peripheral blood and…
At a Glance Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm (MDS/MPN) as it shares features of both dysplasia and proliferative neoplasia. It is characterized by a sustained increase of monocytes that have no known reactive cause. Although many cases do show dysplasia in the granulocytic component of the bone marrow, other cases of CMML…
