MLAB 1415- HEMATOLOGY
KERI BROPHY-MARTINEZ
Myelodysplastic Syndromes
MYELODYSPLASTIC SYNDROMES
• Acquired clonal hematologic disorders
characterized by progressive cytopenias in
the peripheral blood, reflecting defects in
erythroid, myeloid and/or megakaryocytic
maturation.
• Impaired hematopoiesis.
• Disrupted apoptosis
• Bone marrow is hyperplastic
• The origin is currently unknown
Terms used to describe MDS
• Preleukemic leukemia or syndrome
• Chronic refractory anemia with sideroblasts
• Smoldering leukemia
Risk factors
• Age
• Occur primaroy over the age of 50
• Genetic predisposition
• Chromosomes 5,7 and 8
• Down’s, Fanconi’s
• Environmental exposures
• benzene
• Prior therapy
• Radiation
• Chemotherapy
Clinical findings
• Symptoms are related to progressive bone marrow failure
• Infections
• Bleeding
• Anemia- fatigue/weakness
• Death usually occurs from infection and/or bleeding or
from leukemia if transformation occurs.
Key Lab Features of MDS
• Dysmyelopoiesis
• Dyserthropoiesis
• Dysmegakaryopoiesis
Dysmyelopoiesis- PB
Dyserthropoiesis- PB
Dimorphic erythrocyte
population
Oval macrocytes
Dysmegakaryopoiesis- PB
Abnormal platelet granulation
Micromegakaryocyte
FAB classification
• 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- 2008
• Refractory anemia (RA) with unilineage dysplasia
• Refractory anemia with ringed sideroblasts (RARS)
• Refractory cytopenia with multilineage dysplasia (RCMD)
• RA with excess blasts (RAEB)
• MDS with isolated deletion of 5q
• MDS, unclassifiable
• Childhood MDS
MDS/MPD Diseases
• 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
• CMML associated with persistent monocytosis
• Atypical Chronic Myeloid Leukemia
• Juvenile Myelomonocytic Leukemia
• MDS/MPD, unclassifiable
Chronic Myelomonocytic Leukemia (CMML)
• Monocytosis
• Dysplasia in one or more
myeloid lines
• Bone marrow
hypercellular
• Splenomegaly may be
present
Therapy
• Currently, there is no really good treatment for
MDS, therefore most therapy is supportive, such as
transfusion of blood components and antibiotics.
• The only effective treatment is bone marrow
transplant, but most patients are too old to survive
the rigors of this treatment.
• Immunosuppressive therapy decreases the chance
of leukemic transformation.
References
• McKenzie, Shirlyn B., and J. Lynne. Williams. "Chapter
21." Introduction. Clinical Laboratory Hematology. Boston:
Pearson, 2010. Print
• Rodak, Bernadette F., Fritsma, George, and Elaine
Keohane. "Chapter 35." Myelodysplastic Syndrome.
Hematology Clinical Principles and Applications. St. Louis:
Elsevier, 2012. Print