18. Myeloproliferative Neoplasms Flashcards
1
Q
MYELOPROLIFERATIVE NEOPLASMS (MPN)
A
- Disorders of the hematopoietic stem cell that result in over production of the erythrocytes, granulocytes, and/or platelets
- result in the over accumulation of these cells in the marrow and/or blood.
- Extramedullary hematopoiesis - Liver/Spleen
- Panmyelosis-inc in all cell lines
- Less than 20% blast cells
- Malignant transformation (to acute leukemia)
2
Q
Chronic Myelogenous Leukemia (CML)
A
- type of MPN
- Cell line: Myeloid (neutrophils, eosinophils, basophils)
- disease of middle ages (46-58)
- Extramedullary granulocytic proliferation in spleen and liver
- Three phases: chronic, accelerated, and acute (blastic phase)
- Philadelphia chromosome t(9,22) in 95% of patients (better prognosis)
3
Q
Polycythemia Vera (PV)
A
- type of MPN
- Cell line: Erythroid
- Occurs between 40-60 years of age.
- More frequently in males.
- Cardiovascular disease, splenomegaly(75%), hepatomegaly (40-50%).
- Treatment with phlebotomy and myelosuppressive therapy.
- Acute leukemia may develop in 5-10% patients
4
Q
Essential Thrombocythemia (ET)
A
- type of MPN
- Cell line: Megakarytocytic
- Peak incidence 50-60 years of age
5
Q
Primary Myelofibrosis (PMF)
A
- type of MPN
- Cell line: Fibroblast
- Bone marrow fibrosis
- Extramedullary hematopoiesis
- Ineffective erythropoiesis
- Abnormal megakaryocute production
6
Q
Philidelphia chromosome
A
- translocation of gene 9 and 22
- results in increase of BCR-ABL which increases tyrosine kinase activity
- Tyrosine kinase: dives cell proliferation and overrides normal regulatory control (apoptosis)
7
Q
CML blood findings
A
- Extreme leukocytosis (200-500 x 109/L)
- Platelets increased in over half of patients early in disease
- Shift to the left with a myelocytic peak
- Blast count often <10 %
- Eosinophils and basophils are often increased
- Anemia in majority of patients
- LAP (Leukocyte alkaline phosphatase) low
8
Q
CHRONIC PHASE of CML
A
- Insidious onset
- Symptoms are often not present (asymptomatic)
- Increased weakness, unexplained fever, night sweats, and weight loss.
- The chronic phase may last several months to years.
9
Q
Accelerated phase of CML
A
- disease progression
- Without treatment, about 30-40 months after diagnosis, worsening of symptoms
- WBC count increased
- Blasts inc (5-19%)
- Refractive (no response) to previous chemo.
- The leukemic cells may have new chromosome changes, in addition to the Philadelphia Chromosome.
- 30% of patients die before blast crisis
10
Q
Blast phase of CML
A
- There are 20% or more blast cells in the blood/bone marrow.
- Symptoms worsen
- Survival is measured in months
11
Q
Treatment for CML
A
- Gleevec – tyrosine kinase inhibitor
- Supportive treatment-transfusion and antibiotics
- Cytotoxic drugs-remission 2-3 yrs.
- Bone marrow transplant
12
Q
Differences btwen CML and Infection
A
CML:
- Blast and myelocytes as well as more mature forms in peripheral blood
- Absolute basophilia and/or eosinophilia
- Platelets are often increased with abnormal morphological forms present.
- Anemia usually present, nrbc present.
- LAP score is low.
- Ph chromosome positive
Infection:
- Toxic granulation
- Dohle bodies
- Cytoplasmic vacuolization present
- Anemia may be present but nrbc are not typical.
13
Q
Blood Findings of PV
A
- > 95% JAK2 positive
- Absolute erythrocytosis
- Erythrocytes typically appear crowded even at feather edge
- Panmyelosis
- Basophilia
- Shift-to-the left
14
Q
Relative Polycythemia
A
- An increased HCT or RBC as a result of a decreased plasma volume (liquid). The total RBC mass is not increased.
- Caused by acute dehydration such as diarrhea, burns, diuretic therapy.
15
Q
Secondary Polycythemia
A
- High Number of RBC not due to leukemia but due to other things like:
- High altitude- decreased barometric pressure, dec inspired O2, incr 2-3 DPG.
- 2-3 DPG deficiency-dec O2 release to tissue deficiency.
- High affinity Hgb-abnormal Hgb that results in less O2 released to tissues than normal Hgb.
- Tumors-erythropoietin like substance. (50% of renal tumors).
