Myelodysplastic Disorders

Question 1

True or False: both MDS and MPNs have the potential to transform into acute leukemias.

Answer 1

True

Question 2

What are the etiologies of MDS?

Answer 2

De novo (genetic), Exposures (benzene, heavy metals, cigarette smoking), or THerapy-related (prior chemo or radiation)

Question 3

How might a patient with MDS present?

Answer 3

Pancytopenia, Infections, anemia, bleeding

Question 4

What is the pathophysiology of MDS?

Answer 4

Stem cell abnormalities, cytogenetic abnormalities, or subtle molecular abnormalities lead to dysplasia and ineffective hematopoiesis–> apoptosis–> cytopenias

Question 5

What kind of abnormality is the cause of more than 50% of cases of MDS?

Answer 5

Cytogenetic (karyotypic) abnormalities

Question 6

What is a complex deletion?

Answer 6

The term for more than 3 cytogenetic abnormalities

Question 7

What cytogenetic abnormalities are often associated with therapy-related MDS?

Answer 7

Deletion of 5q or 7q

Question 8

What are the good risk factors for MDS?

Answer 8

Normal cytogenetics, isolated loss of 5q, isolated 20q-, or lost Y

Question 9

What are the poor risk factors for MDS?

Answer 9

Complex abnormalities or any Ch. 7 abnormalities

Question 10

For a diagnosis of MDS, what % of cells in a particular lineage in the peripheral blood should be dysplastic?

Answer 10

> 10%

Question 11

What abnormal findings would be expected on a CBC of a patient with MDS?

Answer 11

Pancytopenia, Anemia is the most common presenting symptom (decreased Hb), MCV is normal or increased, Increased RDW, normal or decreased reticulocyte count

Question 12

What lineage of cytopenia is the most important in the WBC of a pt with MDS?

Answer 12

The absolute neutrophil count

Question 13

What is the exception to the expectation that MDS will present with thrombocytopenia?

Answer 13

Thrombocytosis is found in isolated 5q- syndrome

Question 14

What morphologic classification of anemia is seen with MDS?

Answer 14

Usually macrocytic but may be dimorphic in sideroblastic subtypes

Question 15

What abnormal PBS findings would be seen in a pt with MDS?

Answer 15

Basophilic stippling; Anisopoikilocytosis, macrocytic anemia, Howell-Jolly bodies, irregular nRBCs

Question 16

What abnormalities would be seen in the bone marrow of a pt with MDS?

Answer 16

Erythroid hyperplasia or hypoplasia, magaloblastoid changes, asynchronous nuclear-cytoplasmic maturation, large nuclei with red cytoplasm (nucelus cytoplasm disynchrony), ring sideroblasts, broad based nuclear budding, abnormal nuclear shapes, increased pyknosis and karyorrhexis, multinucleation, internuclear bridging

Question 17

Describe the dysgranulopoiesis that occurs in MDS?

Answer 17

Nuclear hyposegmentation in neutrophils (bi- or mono- lobation); Hypo- or hypergranular cytoplasm; doughnut-shaped nuclei, increased myeloblasts and immature granulocytes, and neutropenia

Question 18

Describe the dysmegakaryocytopoiesis that can occur in MDS?

Answer 18

Thrombocytopenia, large platelets, hypogranular platelets, abnormal platelet granules, and micromegakaryocytes

Question 19

What is the most common refractory cytopenia with unlilineage dysplasis (RCUD)?

Answer 19

Refractory anemia

Question 20

What are the specific MDS that are classified as RCUDs?

Answer 20

Refractory anemia, refractory thrombocytopenia, and refractory neutropenia

Question 21

What PB and BM changes are seen in refractory cytopenia with multilineage dysplasia?

Answer 21

Bi- or pancytopenia in PB; dysplastic changes in >10% of the cells in 2 or more cell lines

Question 22

Which is the only MDS in which Auer rods are seen?

Answer 22

RAEB-2

Question 23

What is the difference between RCMD and RCMD-RS?

Answer 23

RCMD is refractoryy cytopenia with multilineage dysplasia with >15% ringed sideroblasts in the marrow

Question 24

What is the prognosis for RAEB-1 and -2?

Answer 24

Poor- median survival is 16 and 10 mo respectively

Question 25

Which is the more aggressive RAEB and why?

Answer 25

RAEB-2 because it can easily progress to >20% blasts= AML

Question 26

What abnormal findings would be seen in the PB and BM of a pt with 5q- syndrome?

Answer 26

Severe refractory anemia, thrombocytosis in blood; Marrow- increased megakaryocyes (many with hypolobation)