Myelodysplasia Flashcards

1
Q

[MYELODYSPLASIA (MDS)]

  • Group of acquired haematopoietic stem cell disorders (~ 4 per 100,000 persons) and typically a disorder of the elderly.
  • Cells are proliferating actively but not effectively.
  • The cells would have an abnormal morphology.
  • Increased number of blasts but ________
  • There is a tendency to develop into _________.
  • Associated with prior exposure to _________________.
  • Normal BM has <5% blasts
A

<20%;

AML (blasts >20%);

alkylating agents or radiotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

[Pathophysiology of MDS]

Haematopoietic stem cells keep on producing abnormal ineffective blast cells

Most of these blast cells are unable to mature properly due to gene mutation, leading to ______________

However, they lack the oncogenic mutation that allows them to ________________.

Even when some of these blast cells DO develop into mature blood cells, they are defective + die off quicker
There is thus ↓ in myeloid cells 🡪 cytopenia 🡪 require _______________

Cytopenia can involve 1 or multiple cell lineages. Pt with MDS therefore present very similarly to patient with Leukaemia.

In summary
- There is an abnormal maturation of blood cells which results in
Cytopenias
- Even in matured cells, there are functional defects causing early death
- Increased Blasts (<20%)
- Increased risk of transformation to ___________ (usually considered a premalignant condition)

A

increase in % blasts;

proliferate indefinitely;

constant transfusion;

leukaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the clinical features for MDS?

A

Anaemia: Fatigue, breathlessness

Thrombocytopenia:

  • Bruising with minimal trauma or blood blisters in the mouth
  • Physical findings include ecchymosis, bleeding gums and epistaxis.

Neutropenia: Infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the investigations performed for MDS?

A

If Refractory anaemia with excess of blasts-1 and 2
- Increased proportion of blast cells in marrow (normal < 5%)

Possible dysplasia we may see in PBF/BM include:

Neutrophils

  • Pelger-Huet anomaly (bilobed neutrophils connected by thin strand)
  • Hypersegmented Neutrophils (also seen in vit B12/folate deficiency)
  • Hyposegmented Neutrophils (pseudo pelger-huet)
  • Auer Rods (seen in AML as well as REAB-2)
  • Dysgranulopoieses of neutrophils (absence / abnormal granules)

RBC

  • Binucleated erythroid precursors
  • Dyserythropoiesis of red cells (abnormal morphological forms - cytoplasmic/nuclear bridging, etc.)
  • Ringer Sideroblasts (Refractory anaemia with ring sideroblasts (RARS)

Megakaryocytes
- Dysplastic megakaryocytes e.g. micro-megakaryocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the prognosis of MDS?

A

Development of acute myeloid leukaemia

  • Develops in 50%< 1 year
  • Some cases of MDS are much slower to evolve
  • AML from preceding MDS extremely poor prognosis; usually not curable

As a rule of thumb

  • 1/3 die from infection
  • 1/3 die from bleeding
  • 1/3 die from acute leukaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the management of MDS?

A

At present, the only 2 treatments that can prolong survival:

  • Allogeneic stem cell transplantation (SCT): Usually done for pt <50YO with a HLA matched sibling
  • Intensive chemotherapy but only a minority of MDS patients can really benefit from them

Supportive:

  • Blood product support, antimicrobial therapy, growth factors (EPO, G-CSF)
  • Biological modifiers: Immunosuppresive therapy/ Azacytidine/ Lenalidomide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly