Myeloproliferative Neoplasms

Update on the Biology of Myeloproliferative Neoplasms

Introduction Single cell origin of hematopoiesis is considered to be a hallmark of all myeloid malignancies. In hematological malignancies, the mutations initiating stem cell clonality can have various forms such as translocated chromosomes, chromosomes with deleted or amplified regions, or point mutations in single genes. Once a stem cell clone has been established, it expands […]

Do We Need Biological Studies for Patient Management? (Myeloproliferative Neoplasms)

Introduction Management decisions for patients with MPN vary between the different disease entities and must include of course the achievement of an accurate diagnosis. For patients with essential thrombocythaemia (ET) and polycythaemia vera (PV), initial disease management most commonly focuses upon preventing thrombotic events, ideally without exacerbating the risk of bleeding. However, a further important […]

Critical Issues About the Diagnosis of MPNs: Bone Marrow Histopathology (General Issues in the Management of MPNs) (Myeloproliferative Neoplasms) Part 1

Introduction Although the revised 2008 World Health Organization (WHO) criteria (Swerdlow et al. 2008) for the diagnosis and classification of Philadelphia chromosome-negative chronic mye-loproliferative neoplasms (MPNs) was defined by a panel of expert hematopathologists and clinicians,serious concern has been repeatedly expressed for its emphasis upon specific histological bone marrow (BM) features (Spivak and Silver 2008). […]

Critical Issues About the Diagnosis of MPNs: Bone Marrow Histopathology (General Issues in the Management of MPNs) (Myeloproliferative Neoplasms) Part 2

Standardization of the WHO Morphological Criteria The complex composition of BM tissue, particularly its changes associated with a malignant hematopoietic process warrants special care concerning the recognition of characteristic his-tological patterns that may be readily assigned to certain disease entities. Hematopathologists and clinicians are aware of the unwanted impact of subjectivity and therefore insist on […]

Critical Issues About the Diagnosis of Myeloproliferative Neoplasms: World Health Organization Classification (General Issues in the Management of MPNs)

Polycythaemia Vera Polycythaemia vera (PV) is a primary bone marrow disorder where excessive numbers of red blood cells are produced. A somatic gain-of-function mutation of the Janus Kinase (JAK) 2 gene is present in most cases. The disease may present in a latent form where there is only a borderline erythrocytosis, the classical overt polycythaemia […]

Patient’s Information and Examinations Needed Before Planning Therapy in the Myeloproliferative Neoplasms (General Issues in the Management of MPNs)

Introduction Patient communication represents an important element of the clinical work of the treating physicians, with this especially applying to individuals with neoplastic diseases, as it is the case of the myeloproliferative neoplasms (MPNs). In the current Internet era, an increasing number of patients seek for information in the network, and, very often, misinterpretation of […]

Mechanisms of Thrombogenesis (General Issues in the Management of MPNs) (Myeloproliferative Neoplasms) Part 1

Introduction The life expectancy of patients with polycythemia vera (PV) and essential thrombocythemia (ET) is strongly affected by disease-related hemostatic complications, including thrombosis and, to a lesser extent, hemorrhages. Reported incidence of thrombosis ranges from 12% to 39% in PV and from 11% to 25% in ET. The clinical manifestation of thrombosis varies from microcirculatory […]

Mechanisms of Thrombogenesis (General Issues in the Management of MPNs) (Myeloproliferative Neoplasms) Part 2

JAK2V617F Mutation The demonstration of the acquired gain-of-func-tion V617F mutation in the tyrosine kinase JAK2 gene (Baxter et al. 2005; Kralovics et al. 2005; Levine et al. 2005; Zhao et al. 2005) has greatly influenced the diagnostic and therapeutic approach in MPN patients. Several studies have implicated JAK2V617F mutation in the increased thrombotic tendency observed […]

Risk Classification (Specific Issues of Treatment in PV and ET) (Myeloproliferative Neoplasms) Part 1

Polycythemia Vera Early studies in untreated PV patients found a high incidence of thrombotic events and a life expectancy of about 18 months after diagnosis (Chievitz and Thiede 1962). Cytoreductive treatments of blood hyperviscosity by phlebotomy or chemotherapy have dramatically reduced the number of thrombotic events, even though hematological transformations towards post-polycythemic myelofibrosis and acute […]

Risk Classification (Specific Issues of Treatment in PV and ET) (Myeloproliferative Neoplasms) Part 2

Leukocyte Number and Function A prognostic role for leukocytosis in ET, as in PV, has been advocated.Two large cohort studies reported that an increased baseline leukocyte count was an independent risk factor for both thrombosis and inferior survival (Wolanskyj et al. 2006; Carobbio et al. 2007) . In "low-risk" ET patients (i.e. below 60 years […]

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