MYELODYPLASTIC SYNDROME Flashcards Preview

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Flashcards in MYELODYPLASTIC SYNDROME Deck (15):
1

What is myelodysplastic syndrome?

Clonal haemopoietic disorders characterised by ineffective haemopoiesis resulting in peripheral blood cytopenia (especially anaemia). There is an increased risk of developing acute leukaemia.

2

What age group is most commonly affected by myelodysplastic syndrome?

Elderly - 60-75 but it does affect younger people as well

3

Are the majority of cases of myelodysplastic syndrome primary or secondary?

Primary

4

What are the causes of secondary myelodysplastic syndrome?

Exposure to occupational chemicals especially benzene
Previous high dose chemotherapy (eg before bone marrow transplant) or radiotherapy

5

How do secondary therapy related cases of myelodysplastic syndrome compare to cases of primary myelodysplastic syndrome?

Therapy related MDS involves:
More severe cytopenia
Occurrence at younger age
A higher rate of transformation into acute leukaemias
More clonal chromosomal abnormalities
A generally poorer prognosis

6

What is the pathogenesis of myelodysplastic syndrome?

DNA damage of a pluripotent stem cell leads to development of myelodyplastic clone which has a growth advantage. Increased cellular proliferation within bone marrow results in hypercellular marrow. However, these cells do not differentiate properly and there is increased rate of apoptosis. Therefore, fewer mature cells leave the bone marrow, resulting cytopenia.

7

How might someone with myelodysplastic syndrome present?

Often asymptomatic and found on incedental FBC
Signs and symptoms of pan-cytopenia: fatigue, shortness of breath, bleeding, infection

8

What investigations should be ordered for someone with suspected myelodysplastic syndrome?

FBC
Blood film
B12
Folate
Bone marrow aspirate and trephine biopsy
Cytogenetics - presence of same cytogenic abnormality in multiple cells in the marrow

9

What are the changes seen on a blood film of someone with myelodysplastic syndrome?

Red cells:
Macrocytosis
Anisocytosis (abnormal size)
Poikilocytosis (abnormal shape)
Basophilic stippling

White cells:
Hypogranular
Unusual nuclear shape

Platelets;
Hypogranular

10

What are the three main types of myelodysplastic syndrome?

Refractory anaemia

Refractory anaemia with ringed sideroblasts

Refractory anaemia with excess blasts

11

What are the changes that might be seen on bone marrow biopsy from someone with myelodysplastic syndrome?

Ringed sideroblasts
Increased blasts
Megakaryocytes with separated nuclei

12

What is the prognosis of someone diagnosed with myelodysplastic syndrome?

6 months to 6 years

13

How are myelodysplatic syndrome patients managed?

Supportive transfusions of red cells and platelets
EPO injections may reduce number of transfusions needed - particularly useful in refractory anaemia with ringed sideroblasts
Immunosuppressives such as ciclosporins or antithymocyte globulins
Allogeneic stem cell transplant

14

What is the genetic abnormality associated with myelodysplastic syndrome in middle aged woman which is associated with a longer survival and a lower risk of transformation into acute myeloid leukaemia?

Loss of the long arm of chromosome 5

15

What drug is useful in treating patients with myelodysplastic syndrome associated with 5q- (loss of long arm of chromosome 5)?

Thalidomide analogues such as lenalidomide