View source for Myelodysplastic Syndromes

These conditions involve blood cell dysplasias, which result from reductions in blood cell counts or abnormal production.
{| class="wikitable"
! rowspan="2" |Condition
! rowspan="2" |Cause
! colspan="2" |Lab Findings
! rowspan="2" |Diagnostic Tests
! rowspan="2" |Treatment
|-
!Peripheral Blood
!Bone Marrow
|-
|Myelodysplastic Syndromes (general)
|Usually, translocations
|Dysplasia of myeloid cell lines
|<20% blasts
|
* Cytogenetic testing
* Molecular testing
* Immunological marker (CD marker) testing
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|-
|Dyserythropoiesis
|
|
* Oval macrocytes
* Hypo/micro picture
* Dimorphic population
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* Erythroid hyperplasiaAbnormal RBC precursors

* Multiple nuclei
* Abnormal nuclear shapes (nuclear budding, nuclear bridging)
* Uneven staining
* Ringed sideroblasts
* Basophilic stippling
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|
|-
|Refractory Anemia

* Form of dyserythropoiesis
|
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* Anemia
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* Bone marrow erythrodysplasia
* Ringed sideroblasts in >15% of nucleated erythroid precursors
** Iron mitochondria surrounding >1/3 of nucleus
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|-
|Dysmyelopoiesis
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|Neutrophils (>90% showing dysplasia)

* Uneven cytoplasm staining and basophilia
* Abnormal granulation (hypo-, hyper-, or agranulation)
* Abnormal nuclear segmentation (hypo, rarely hyper)
** pseudo-Pelger-Huet forms
* Possibly nuclear rings (doughnut-shaped)
* Nuclear asynchrony
** Mature, clumped chromatin but immature shape
|
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|Dysmegakaryocytopoiesis
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* Thrombocytopenia (60%)
* Giant platelets
* Hypo- or agranulation
* Micromegakaryocytes with fused granules
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* Megakaryocytes with abnormal morphology
** May have small, separated nuclei
* Micromegakaryocytes and micromegakaryoblasts
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|-
|Chronic myelomonocytic leukemia (CMML)
|
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* Monocytosis >1.0x10<sup>9</sup>/L
* ↑ leukocytes
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* <20% blasts
* Dysplasia in 1+ myeloid cell lines
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|}
Differential Diagnosis

Many other conditions can have findings similar to myelodysplastic syndromes. 

* Vitamin B12 or folate deficiencies
* Heavy metal exposure
* Fanconi anemia, congenital dyserythropoietic anemia
* Parvovirus B19
* Chemotherapy agents
* Paroxysmal cold hemoglobinuria
* HIV