Neoplastic WBC II

• Myeloproliferative neoplasms are clonal stem cell disorders that involve abnormally low apoptosis or abnormally high proliferation
• In myeloproliferative neoplasms, bone marrow is often hypercellular with increased amounts of one or more myeloid lineages
• In myeloproliferative neoplasms you generally see cytosis
• Cytosis: increased number of the type of cell affected
• Myeloproliferative neoplasms are often associated with translocations or point mutations that involve enhanced expression of proteins participating in anti-apoptotic pathways
• Myeloproliferative neoplasms have the potential to terminate in bone marrow failure
• Chronic myeloid leukemia has a median age of 67 years and 20-40% of patients are asymptomatic
• Laboratory findings for CML include CBC showing leukocytosis and t(9;22) BCR-ABL1
• CML has 3 phases: 1) chronic 2)accelerated 3)blast
• The majority of CML cases present in the chronic phase
• The chronic phase of CML is marked by leukocytosis, no dysplasia and basophilia in the peripheral blood
• The chronic phase of CML is marked by hypercellular bone marrow and dwarf megakaryocytes
• The accelerated phase of CML is marked by disease progression and 10-19% blasts in the bone marrow or peripheral blood
• The blast phase of CML is marked by >20% blasts in the peripheral blood or marrow and most cases are acute myeloid leukemia while ~25% are acute lymphoblastic leukemia
• The cytogenetic marker for CML is t(9;22) BCR/ABL1
• CML in the chronic phase can be treated with tyrosine kinase inhibitors
• CML in the accelerated phase can be treated by switching TKIs
• CML in the blast phase can be treated as acute leukemia with bone marrow transplant
• Polycythemia vera is increased red blood cell production independent of normal mechanisms
• Clinical findings for polycythemia vera are most related to hyperviscosity and platelet dysfunction
• One unique symptoms associated with polycythemia vera is pruritis after bathing
• Lab findings for polycythemia vera involves increased RBC mass and low erythropoietin level
• A patient with polycythemia vera will have hypercellular bone marrow and decreased or absent iron stores
• The progression phase of polycythemia vera is the spent phase when the marrow can become fibrotic
• Treatment for polycythemia vera involves preventing complications with phlebotomy, anti-thrombotics and JAK2 inhibitors
• Polycythemia vera has a good prognosis with a survival of >10 years
• Secondary polycythemia can be caused by physiologically appropriate and inappropriate factors
• Relative polycythemia vera can be caused by decreased plasma volume
• Essential thrombocythemia is caused by a sustained increase in platelets with no primary/underlying cause
• 50% of patients with essential thrombocythemia are asymptomatic and most are asymptomatic at diagnosis
• Clinical findings for essential thrombocythemia are thrombosis and hemorrhage
• Lab findings for essential thrombocythemia are increased platelets and JAK2 gene mutations
• Essential thrombocythemia bone marrow findings will include an increased number of large hypersegmented megakaryocytes with "staghorn" nuclei
• Essential thrombocythemia can be treated with JAK2 inhibitors and anti-thrombotics
• During the spent phase of essential thrombocythemia, the bone marrow becomes fibrotic. It can also progress to AML but the risk is lowest of all myeloproliferative neoplasms
• Essential thrombocythemia has a good prognosis with a survival rate of >10 years
• Primary myelofibrosis involves the proliferation of granulocytes and megakaryocytes with deposition of fibrosis
• The major clinical findings for primary myelofibrosis is abdominal pain due to splenomegaly
• The most common gene mutations with primary myelofibrosis are JAK2, CALR and MPL
• The pre-fibrotic phase of primary myelofibrosis is noted by increased granulocytes in bone marrow