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Myelodysplasia

 

 

 

Myelodysplastic Syndromes/Neoplasms (MDS)

 

These are clonal disorders characterized by:

  • Cytopenia(s) and dysplasia in one or more of the major myeloid cell lines,
  • Ineffective hematopoiesis
  • Increased risk of developing AML.

The incidence is 1.8 per million per year in children aged up to 14 years.

Accounts for 4% of hematological malignancies.

Due to an acquired clonal disorder of hematopoietic progenitor cell.

  • Growth advantage of clonal cells
  • Disturbed differentiation
  • Increases apoptosis

Causes ineffective hematopoiesis with dysplasia. Clonal cells can still undergo apoptosis though and so blast cells do not predominate in the marrow.

Can start in one cell line

Usually progresses to pancytopenia and bone marrow failure

Transformation to AML common

Often have cytogenetic abnormalities eg. abnormalities of chromosomes 8, 7, 5, 20, 17 and Y

Sometimes called “preleukemia"

 

Stem Cells involved by MDS may be:

Pluripotent Stem cell

involved in

Myelopoiesis
Erythropoiesis
Megakaryopoiesis
Lymphopoiesis

Multipotent Stem cell restricted to involvement in

Myelopoiesis

Erythropoiesis
Megakaryopoiesis

 

Links:

Myelodysplastic Syndromes at the National Cancer Institute

Childhood Myelodysplastic Syndromes at the Atlas of Genetics and Cytogenetics in Haematology and Oncology

 

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