Myelodysplastic Syndrome & Myeloproliferative Neoplasms Flashcards
List the 2 main features that characterize myelodysplastic syndrome (MDS).
- Ineffective Hematopoesis
2. Increased risk of transformation to acute leukemia
List the 2 clinical scenarios of MDS.
- Primary, idiopathic MDS- Elderly (median age 70), 3-5/100,000 per year
- Secondary, therapy related MDS- Diagonses 2-8 years post therapy (DNA alkylating or ionizing radiation), complex karyoptype (part/full del. ch 5/7)
List 3 different Signs of MDS that can lead to a diagnosis
- Persistent peripheral cytopenia in 1+ lineages
- If only one lineage, it is almost always persistent anemia
- Persistent cytopenia in 2+ lineages in patients of advanced age
List 3 different types of tests that could be performed to make a diagnosis of MDS.
- morphological evidence of dysplasia (Look at a smear, or karyotype)
- Increased myeloblasts (but less than 20% of blood/marrow)
- Presence of clonal cytogenetic abnormalities
List 4 possible causes of secondary myelodysplasia that might mimic MDS.
- Vitamin Deficiency (B12, folate)
- Toxin Exposure (Heavy metals)
- Exposure to certain drugs
- Viral infections
Pelgeroid Cells (Image)
Dysplastic neutrophils with two lobes
Low Grade MDS
Myeloblasts are not increased in frequency (<2% in blood)
High Grade MDS
Myeloblasts are increased in frequency, but less than 20% (myeloblasts account for 5-19% of marrow cells, and/or 3-19% of blood cells)
Refractory Cytopenia with Unilineage Dysplasia, RCUD
Low grade
Relatively good prognosis
Refractory anemia with Excess Blasts 1- RAEB-1
High Grade
Relatively Dismal prognosis
5-9 in marrow, 2-4 in blood
Myeloproliferative Neoplasms (MPNs)
Arise from transformed hematopeotic cells (Like MDS)
Still effective hematopeosis however
Younger patients than MDS
Marrow growing too much
List 2 reasons for the frequent occurrence of splenomegaly and hepatomegaly in patients with MPNs.
- Too many cells, so they’re sequestered in the two organs
2. Transition to extramedullary production of blood cells with marrow fibrosis
List 3 possible negative end points for MPNs.
- Excessive marrow fibrosis (marrow aging and scarred)
- Transform to acute leukemia
- The two megaly’s
Refractory Cytopenia with Multilineage Dysplasia (RCMD)
Low Grade
Dysplasia in 2 or more lineages
Worse prognosis than RCUD
10% transform to AML
Chronic Myelogenous Leukemia (CML)
Increased WBC (12,000 to 1,000,000) Neutrophilic leukocytosis
Increased basophils and often platelets
If untreated, goes to blast phase (basically acute leukemia)
Polycythemia Vera (PV)
Increased in RBC mass
Sometimes increased neutro’s and plts
Transforms to spent phase (fibrotic marrow, bone marrow failure)
Primary Myelofibrosis (PMF)
Granulocytic and megakaryocytic hyperplasia
Leukoerythrobastosis- more immature cells than usual (both RBC and WBC)
Teardrops in the bloodsmear because squeezed out marrow
The two megaly’s due to extramedullary hematopoesis
Essential Thrombocythemia (ET)
Just increased megakaryocytes -> increased plts
Refractory Anemia with Excess Blasts-2 (RAEB-2)
High grade
“Very dismal”
10-19% blasts in marrow, and/or 5-19% blasts in blood
Explain why there is a need for a second and third generation of protein tyrosine kinase inhibitors (PTKIs).
Cancer has developed resistance through mutations involved imatinib binding sites
List 3 sites where thrombosis should always make one consider the possibility of PV.
- ) Mesenteric Vein
- ) Hepatic Portal Vein
- ) Splenic Vein
The most common method of death attributable to disease in polycythemia vera (PV) patients
Thrombotic events
Describe findings that might be seen in a peripheral blood smear of a patient with leukoerythroblastosis and how these findings relate to patients with marrow fibrosis.
A lot of immature WBCs and RBCs in peripheral blood because the firbrosis is forcing the blasts out of the marrow sooner
Dacryocytes
Chronic Myelogenous Leukemia (CML)
Cytogenic Finding
BCR-ABL gene fusion t(9;22), philadelphia chr. fusion protein
