MLAB 1415- Hematology
Keri Brophy-Martinez
Chapter 23:
Myelodysplastic Syndromes
MYELODYSPLASTIC
SYNDROMES
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A group of acquired clonal hematologic
disorders characterized by progressive
cytopenias in the peripheral blood, reflecting
defects in erythroid, myeloid and/or
megakaryocytic maturation.
Bone marrow is hyperplastic
The result in impaired hematopoiesis.
The origin is currently unknown.
Affects people over 50 with a slight male
predominance
Terms used to describe MDS
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Preleukemic leukemia or syndrome
Preleukemic acute human leukemia
Chronic refractory anemia with
sideroblasts
Smoldering leukemia
Risk factors
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Age
Genetic predisposition
• Chromosomes 5,7 and 8
• Down’s, Fanconi’s
Environmental exposures
• benzene
Prior therapy
• Radiation
• Chemotherapy
Clinical findings
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Symptoms are related to progressive bone marrow
failure
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Infections
Bleeding
Weight loss
Cardiovascular
Death usually occurs from infection and/or bleeding
or from leukemia if transformation occurs.
Hematologic abnormalities in
MDS
Findings
Erythroid
Myeloid
Thrombocyte
Peripheral blood
Anemia
Macro, oval
macro,basophilic
stippling, nRBC,
Howell-Jolly
bodies,sideroblasts
aniso, poik
•Neutropenia
•Dysgranulopoiesis:
Agranular or
hypogranular neutrophils,
Abnormal granulation of
neutrophil precursors,
Hyposegmented
neutrophils
•Thrombocytopenia/thro
mbocytosis
•Hypogranulation
•Micromegakaryocytes
•Functional abnormalities
•Giant platelets
Bone Marrow
•Megaloblastic
erythroblasts
•nuclear fragments
•multiple nuclei
•vacuoles
•Abnormal granules in
promyelocytes
•Absence of secondary
granules
•Auer rods in blasts
•Micromegakaryocytes
•Megakaryocytes with
multiple nuclei
•Hypogranulation
Dysgranulopoiesis
FAB classification
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Five MDS subtypes:
• Refractory anemia (RA)
• Refractory anemia with ringed sideroblasts
(RARS)
• Refractory anemia with excess blasts (RAEB)
• Refractory anemia with excess blasts in
transformation (RAEB-t)
• Chronic myelomonocytic leukemia (CMML)
WHO classification
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Refractory anemia (RA)
• Anemia is primary finding, but unresponsive to treatment
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Refractory anemia with ringed sideroblasts (RARS)
• >15% ringed sideroblasts in bone marrow
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Refractory cytopenia with multilineage dysplasia (RCMD)
• Dysplastic features in at least 10% of cells in two or more lines
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RA with excess blasts-1 (RAEB)
Cytopenia in at least two lineages, with qualitative abnormalities in all
three cell lines
MDS/MPD Diseases
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Clonal hematopoietic neoplasms that at initial presentation
have some clinical, laboratory or morphological findings of both
a MDS/MPD
Abnormalities in the regulation of myeloid proliferation,
maturation and cell survival
Diseases
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CMML associated with persistent monocytosis
Others
Chronic Myelomonocytic Leukemia (CMML)
• Monocytosis
• ↑ in mature monocytes (some forms have ↑
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monoblasts and promonocytes)
Bone marrow hypercellular
Splenomegaly and hepatomegaly (in patients
with high WBC count)
Therapy
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Currently, there is no really good treatment for
MDS, therefore most therapy is supportive,
such as transfusion of blood components and
antibiotics.
Treatments that modulate the immune system,
such as steroids and interferon have been
used to some success.
The only effective treatment is bone marrow
transplant, but most patients are too old to
survive the rigors of this treatment.
References
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McKenzie, Shirlyn B., and J. Lynne.
Williams. "Chapter 21." Introduction.
Clinical Laboratory Hematology. Boston:
Pearson, 2010. Print