MLAB 1415- Hematology Keri Brophy-Martinez Myelodysplastic Syndromes

MYELODYSPLASTIC SYNDROMES Acquired clonal disorders characterized by progressive cytopenias in the peripheral blood, reflecting defects in erythroid, myeloid and/or megakaryocytic maturation. Impaired hematopoiesis. Disrupted apoptosis 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 primarily 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 Dyserythropoiesis Dysmegakaryopoiesis

Dysmyelopoiesis- PB

Dyserythropoiesis- 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