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Myelodisplastic Syndromes


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Myelodysplastic Syndromes
Clonal stem cell diseases with ineffective hematopoeisis

-abn hematopoeitic cells are ind the BM, don't migrate well to PB
Myelodysplastic features
Blood cytopenia
marrow hyperplasia

no lymphadenopathy or splenomegaly
Myelodysplastic syndromes progress to?
AML, very bad prognosis
Causes of Myelodysplasia
-Primary (idiopathic)
-Secondary to drug, radiation, heavy metals, viral infections, megaloblastic anemias, congenital dyserythropoietic anemia, PNH
Mean age onset of myelodysplastic syndromes
About 70 years old
Abnormal RBC prodruction
Features of myelodysplasia
-irregular nuclear borders
-megaloblastoid change (inc n/c ratio)
-ringed sideroblasts
-PAS +
How do you know the difference between primary and secondary myelodysplastic syndromes?
-Cytogenetic abnormalaties point to primary MDS
-No cyto abnormalaties means it's primary or secondary MDS
Dysgranulopoeisis morph features
-small cell size, hypogranulation, nuclear hypersegmentation or hypolabation, pseudo Cheidiak-Higashi granules, Pseudo Pelger-Huet cells
Dysmegakaryocytopoiesis morph features
Hypolobation or multinucleation, hypogranular platelets
Atypical localization of immature precursors
ALIP is...
clusters of myeolblasts and promyelocytes away from vascular structures
ALIP is commonly seen in?
-Higher grade Myelodysplastic syndromes

-indicates a more rapid evolution to acute leukemia
Grades of Primary myelodysplastic syndromes
Low grade- 1-refractory anemia 2-refractory anemia with ringed sideroblasts

High grade- 1-refractory cytopenia with multilineage dysplasia 2-refractory anemia with excess blasts
Risks of high grade myelodysplastic syndromes
Transformation to AML, which is refractory to treatment
Natural progression of MDS without treatment
Low grade MDS evolves to High grade MDS which evolves to acute leukemia (AML) refractory to treatment
Refractory anemia
-Chronic anemia due to ineffective erythropoeisis (normocytic or macrocytic) which is unresponsive to Iron, Vit B12, folate
Dysplasia in Refractory anemia
Only dyserythropoeisis

<1% in pb
<5% in BM
Cytogenic abnormalities in refractory anemia
-about 25% have them
-Median survival of 5-6 years
-Progression to acute leukemia in <10%
Refractory anemia with ringed sideroblasts
Like refractory anemia but 15% or more of the erythroid precursors in the BM are ringed sideroblasts
Secondary causes of ringed sideroblasts (must be excluded for refractory anemia with ringed sideroblast diagnosis)
Anti-TB drugs and Alcoholism
Dysplasia seen in Refractory anemia with ringed sideroblasts
-Dysplasia limited to dyserythropoiesis
-Myeloblasts <1% in PB, <5% in BM
Refractory anemia with Ringed sideroblasts cytogenics and survival
-<10% have cytogenetics
Survival ~6yrs
1-2% progression to acute leukemia
Refractory cytopenia with multilineage dysplasia
Bi- or Pancytopenia with dysplastic changes in TWO or THREE lineages
Refractory anemia with multilineage dysplasia cytogenics and survival
Myeloblasts <1% PB, <5% BM,

ab half havecytogenetic abnormalaties

Survival ~3years-10%progress to acute leukemia
Refractory anemia with excess blasts
dysplasia in all three lineages
Types of Refractory anemia with excess blasts
RAEB-1-myeloblasts <5% in PB +/- 5-9% in BM

RAEB-2-myeloblasts <5-19% in PB +/- 10-19% in BM or AUER RODS
AUER RODS or myeloblasts <5-19% in PB +/- 10-19% in BM or AUER RODS
Auer rods
Abnormally packaged myeloperoxidase crystals

Looks like needle shaped red rods in blast cytoplasm
RAEB cytogenics and survival
~half with cytogenic abnormalaties
RAEB-1 median survival 18 months, 25% progress to AML
RAEB-2 median survival 10 months, 30-35% progress to AML
Myelodysplastic/myeloproliferative overlap syndromes
Diseases with myelodysplastic features (abnormal dysplastic morphologic forms) but also myeloproliferative features (usually leukocytosis +/- splenomegaly)
Overlap Syndromes classifications
-Not applied to pts with history of myeloproliferative disorder (transformation) or philadelphia chromosome (CML)

May terminate with cytopenias or blast transformation
Chronic Myelomonocytic Leukemia
Previous classified as MDS

-Persistant, non-reactive, peripheral MONOCYTE cont >1000mL

No philadelphia chromosome, <20% blasts in blood or BM,
Dysplasia seen in CML
Dysplasia in one or more lineage

wbc count variable

splenomegaly common when WBC is high d/t leukemic infiltration
Myeloblasts <5% in blood
<10% in BM
Myeloblasts <5-19% in blood, 10-19% in marrow

CML cytogenics and median Progression
20-40% abnormalities

15-30%progress to AML
Auer rods in blood
Auer rods = AML EXCEPT

RAEB-2 or CMML-2

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