myelodysplastic syndrome. group of clonal disorders of hematopoietic stem cells characterized by...
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Myelodysplastic SyndromeMyelodysplastic Syndrome
Group of clonal disorders of Group of clonal disorders of hematopoietic stem cells hematopoietic stem cells characterized by cellular dysplasia characterized by cellular dysplasia and ineffective hematopoiesis and ineffective hematopoiesis
Results in cytopenias and Results in cytopenias and dysmyelopoiesis dysmyelopoiesis
Variable risk of transformation to Variable risk of transformation to acute leukemia acute leukemia
PathophysiologyPathophysiology
Primary MDS or Secondary MDSPrimary MDS or Secondary MDS A clonal mutation in hematopoietic stem A clonal mutation in hematopoietic stem
cellscells Bone marrow failure due to ineffective Bone marrow failure due to ineffective
hematopoiesis hematopoiesis Increased cytokines (TNF-a) inhibit Increased cytokines (TNF-a) inhibit
hematopoiesishematopoiesis Increased apoptosisIncreased apoptosis Results in futile cycling of blood cells with Results in futile cycling of blood cells with
impaired production of mature blood cells impaired production of mature blood cells
Prevalence Prevalence
Mainly a disorder of older patients, Mainly a disorder of older patients, rarely presents before age 50 rarely presents before age 50
Median age is 65 yearsMedian age is 65 years Male predominance Male predominance
Clinical Presentation Clinical Presentation
Non specific signs and symptoms of various Non specific signs and symptoms of various cytopeniascytopenias
• Fatigue, SOB, exercise intolerance, pallor, Fatigue, SOB, exercise intolerance, pallor, tachycardia tachycardia
• Mucosal bleeding, petechiae, ecchymosesMucosal bleeding, petechiae, ecchymoses• Infection, feverInfection, fever
B-symptoms are uncommon B-symptoms are uncommon Splenomegaly and lymphadenopathy are rareSplenomegaly and lymphadenopathy are rare
Diagnosis Diagnosis
Anemia uniformly present with decreased Anemia uniformly present with decreased reticulocytosisreticulocytosis
>50% present with pancytopenia>50% present with pancytopenia 50% present with associated neutropenia50% present with associated neutropenia <5% isolated neutropenia or <5% isolated neutropenia or
thrombocytopenia thrombocytopenia Cytopenia with normal or hypercellular Cytopenia with normal or hypercellular
bone marrow with single or multi-lineage bone marrow with single or multi-lineage dysplasiadysplasia
Morphology Morphology
Peripheral changes Peripheral changes include oval include oval macrocytic red macrocytic red cells, hypogranular cells, hypogranular granulocytes with granulocytes with the pseudo-Pelger–the pseudo-Pelger–Huët anomaly, and Huët anomaly, and giant platelets. giant platelets.
MorphologyMorphology
Megaloblastic red-Megaloblastic red-cell precursors with cell precursors with multiple nuclei or multiple nuclei or asynchronous asynchronous maturation of the maturation of the nucleus and the nucleus and the cytoplasmcytoplasm
Morphology Morphology
Ringed Ringed sideroblasts, sideroblasts, erythroid erythroid precursors with precursors with iron-laden iron-laden mitochondriamitochondria
ClassificationClassification
DiseaseDisease Peripheral BloodPeripheral Blood Bone MarrowBone Marrow
Refractory Anemia (RA) Anemia
No or rare blasts
Erythroid dysplasia only
< 5% blasts
< 15% ringed sideroblasts
Refractory Anemia with Ringed Sideroblasts (RARS)
Anemia
No blasts
Erythroid dysplasia only >15% ringed sideroblasts < 5% blasts
Refractory cytopenia with multilineage dysplasia (RCMD)
CytopeniaNo or rare blastsNo Auer rods < 1 × 109/L monocytes
Dysplasia in 10% of cells in 2 or more myeloid cell lines < 5% blasts in marrow < 15% ringed sideroblasts
Classification Cont.Classification Cont.Disease Peripheral Blood Bone Marrow
Refractory cytopenia with multilineage dysplasia and ringed sideroblasts (RCMD-RS)
CytopeniaNo or rare blastsNo Auer rods < 1 × 109/L monocytes
Dysplasia in 10% of cells in 2 or more myeloid cell lines < 5% blasts in marrow > 15% ringed sideroblasts
Refractory anemia with excess blasts-1 (RAEB-1)
Cytopenias< 5% blastsNo Auer rods< 1 × 109/L monocytes
Unilineage or multilineage dysplasia 5% to 9% blasts No Auer rods
Refractory anemia with excess blasts-2 (RAEB-2)
Cytopenias 5% to 19% blasts Auer rods ± < 1 × 109/L monocytes
Unilineage or multilineage dysplasia 10% to 19% blasts ±Auer rods
Classification cont. Classification cont.
DiseaseDisease Peripheral BloodPeripheral Blood Bone MarrowBone Marrow
Myelodysplastic syndrome, unclassified (MDS-U)
CytopeniasNo or rare blastsNo Auer rods
Unilineage dysplasia in granulocytes or megakaryocytes < 5% blasts No Auer rods
MDS associated with isolated del(5q)
Anemia < 5% blastsPlatelets normal or increased
Normal to increased megakaryocytes with hypolobated nuclei < 5% blastsNo Auer rodsIsolated del(5q)