Myelodysplastic syndromes

Question 1

What are myelodysplastic syndromes?

These are characterized by what? (3)

Answer 1

Group of disorders featuring ineffective proliferation & differentiation of abnormally maturing myeloid stem cells

Characterized by

1. peripheral cytopenia
2. Risk of AML transformation
3. qualitative abnormalities of cell maturation

by defintion have <20% blast cells (if more = acute leukaemia)

Seen in elderly

Question 2

Clinical features (3)

Answer 2

• BM failure & cytopenias - bleeding, infection, fatigue
• Hypercellular BM
• defective cells
  
  • ​RBCs - ringed sideroblasts (defective iron loading which leads to iron deposition in mitochondria in a ringed fashion around nucleus)
  • WBCs - Pelger-Huet - hyposegmented neutrophils
  • Platelets - micromegakaryocytes, hypolobated nuclei
    *

Question 3

The blood features & BM features in the following myelodysplastic syndromes:

• Refractory anaemia
• Refractory anaemia + Ringed sideroblasts
• Refractory cytopenia with multilineage dysplasia
• Refractory cytopenia with multilineage dysplasia & ringed sideroblasts
• Refractory anaemia with excess blasts -1
• Refractory anaemia with excess blasts-2
• MDS with 5q deletion

Answer 3

Subtype

Blood features

BM features

Refractory anaemia

Anaemia, no blasts

Erythoid dysplasia with < 5% blasts

Refractory anaemia with ringed sideroblasts (RA+RS)

Anaemia, no blasts

Erythoid dysplasia with > 15% ringed sideroblasts

Refractory cytopenia with multi-lineage dysplasia (RCMD)

Cytopenia >/= 2 cell lines

Dysplasia in > 10% cells in >/= 2 cell lines

Refractory cytopaenia with multilineage dysplasia + ringed sideroblasts (RCMD +RS)

Cytopenia >/= 2 cell lines

Dysplasis in > 10% cells in >/= 2 cell lines + >15% ringed sideroblasts

Refractory anaemia with excess blasts -1 (RAEB I)

Cytopenias, <5% blasts (NO auer rods)

Dysplasias, 5-9% blasts

Refractory anaemia with excess blasts-2 (RAEB II)

Cytopenias OR 5-19% blasts OR Auer rods

Dysplasias, 10-19% blasts or auer rods

MDS with 5q deletion

Anaemia, normal/increased platelets

Megakarytocytes with hypolobated nuclei & <5% blasts

Question 4

Rx - supportive, biological, chemo, allogeneic SCT

Prognosis depends on (3)

Answer 4

• supportive - transfusions, EPO, G-CSF, ABs
• biological - IS drugs, lenalidomide
• Chemo - similar to AML
• Allogeneic SCT

Prognososis depends on: BM blast%, karyotype, degree of cytopenia

Mortalitiy rule of 1/3: 1/3 die from infection, 1/3 die from bleeding, 1/3 die from acute leukaemia