MLAB 1415- HEMATOLOGYKERI 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

MicromegakaryocyteAbnormal platelet granulation

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