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Flashcards in Heme Exam 2 Deck (58)
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1

•Heterogeneous group of clonal hematological malignancies characterized by:

•PB cytopenias

•Dysplastic blood cells

•Propensity to transform into acute leukemia

•Almost always fatal

•No curative treatment other than allogeneic stem cell transplantation

•Myelodysplastic Syndromes (MDS)

2

•3 Sequential Phases of Apoptosis in MDS

 

•3 Sequential Phases

•Initiation

•Commitment

•Execution

3

•Factors that initiate apoptosis

•Chemotherapy and Radiotherapy

•Corticosteroids

•Growth factor deprivation

•Direct effect of cytotoxic T-cell activity

•Inhibitory Cytokines

•Tumor Necrosis Factor alpha (TNF-α)

•Transforming Growth Factor beta (TGF-β)

•Action of Fas-ligand on it’s receptor  FAS/CD95

4

•MDS phenotype changes as the disease progresses towards leukemia

•Number of blast cells increases in the marrow

•PB leukocytosis may replace leukopenia

•Hepatosplenomegaly can occur

5

What type of anemia is most common in MDS?

Macrocytic, normochromic

6

What morphological abnormalities are helpful in the diagnosis of MDS?

Pseudo pelger huet, hypogranulation, ringed sideroblasts, micromegakaryocytes, monolobular megakaryocytes

7

What differentiates RAEB-t from AML of the M2 type?

the finding of t(8;21)

8

Which of these cell surface antigens is of prognostic significance in MDS?

CD19

CD HLA-DR

CD34

CD33

CD34

9

Which MDS subgroup has the most favorable prognosis?

RARS

10

What type of treatment may offer a cure in patients with MDS?

Allogeneic bone marrow transplantation

11

What type of agent may lead to secondary MDS (sMDS)?

Alkylating agents

12

Which is most likely to affect prognosis in MDS?

Leukopenia

Increased bone marrow myeloblasts

erythroid hyperplasia

thrombocytosis

Increased bone marrow myeloblasts

13

In female patients with RA and elevated platelets, what chromosome abnormality is most often found?

5q-

14

What genetic abnormality is important in MDS?

Chromosome deletions

15

What MDS scoring system is most widely used today?

 

IPSS

16

•Acceleration of MDS has been associated with:

•Decrease in medullary apoptosis

•Decrease in Fas expression

•Mutation at the p53 (tumor suppressor) and RAS (protooncogene) loci

17

Type I blast

•myeloblast of variable size, w/out azurophillic granules or Auer rods

18

type II blast

•myeloblast that is slightly larger and contain few azurophillic granules (1 to 20)

19

type I sideroblast

•normal siderblast containing 1 to 4 cytoplasmic iron-containing granules

20

type II siderblast

•considered abnormal, harboring 5 to 10 granules; scattered throughout the cytoplasm

21

Sideroblasts

22

•Dyserythropoiesis PB characteristics

•Anemia present in 90% of cases

•Erythrocyte Morphological Characteritics

•Anisopoikilocytosis

•Basophilic stippling

•Dual red blood cell population

•Pappenheimer bodies

•Dacrocytes,

•Fragmented cells

•Howell-jolly bodies

23

•Most difficult MDS to recognize and diagnose

•Dx relies mainly on subjective identification

•Lab Findings

•Anemia- more than 90% of patients

•Normochromic/macrocytic

•WBC- decreased

•Platelet-decrease

•<15% ringed sideroblasts in BM

•Erythroid hyperplasia common

Refractory Anemia

24

MDS subtype

•Dx rests on quantitative criteria:

•Presence of at least 15% ringed sideroblasts in the BM

•Ringed Sideroblasts

•Pathologic sideroblasts in which the usual migration of mitochondria from the nucleus does not occur

•Result: remain frozen around the nucleus, where insoluble iron conglomerates and further contributes to cell destruction

•Lab Features

•RBCs macrocytic or normocytic with dimorphic features

•Leukopenia

•Thrombocytopenia

2.Refractory Anemia w/ Ringed Sideroblasts (RARS)

25

What MDS subtype?

RARS

26

MDS subtype

•Degree of lineage dysplasia more significant

•Blasts ranges from 5% to 20%

•Dysgranulopoiesis with nuclear hyposegmentation and hypogranulation is frequent

•Thrombocytopenia

3.Refractory Anemia with Excess Blasts (RAEB)

27

RAEB

28

RAEB-t

29

CMML

30

•Interstitial deletion of the long arm of chromosome 5

•Classified as having RA; predominantly female

•Elevated platelet count, mild leukopenia

•5q- Syndrome