MYELODYSPLASTIC SYNDROMES

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1 MYELODYSPLASTIC SYNDROMES Babak Tamizi Far MD. Assistant professor of internal medicine Al-zahra university hospital, Isfahan university of medical sciences

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4 Key Features ESSENTIALS OF DIAGNOSIS Cytopenias with hypercellular bone marrow Morphologic abnormalities in two or more hematopoietic cell lines

5 Causes Idiopathic (most common) May be seen after cytotoxic chemotherapy May evolve into acute myeloid leukemia (AML); had been termed "preleukemia" in the past

6 Myelodysplasia encompasses several heterogeneous syndromes Refractory anemia (with or without ringed sideroblasts): no excess bone marrow blasts Refractory anemia with excess blasts (RAEB): 5 19% blasts Chronic myelomonocytic leukemia (CMML): a proliferative syndrome, including peripheral blood monocytosis > 1000/mcL

7 GENERAL CONSIDERATIONS Group of acquired clonal disorders of the hematopoietic stem cell, characterized by cytopenias, usually hypercellular marrow, and morphologic and cytogenetic abnormalities No specific chromosomal abnormality is seen, but abnormalities in chromosomes 5 and 7 are common

8 DEMOGRAPHICS Occurs most often in patients aged > 60

9 Clinical Findings SYMPTOMS AND SIGNS Asymptomatic, with incidentally found cytopenias Fatigue, infection, or bleeding is related to bone marrow failure Wasting, fever, weight loss Splenomegaly Pallor Bleeding Signs of infection

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11 DIFFERENTIAL DIAGNOSIS AML ( 20% blasts) Aplastic anemia Anemic of chronic disease Vitamin B12 or folate deficiency

12 Diagnosis LABORATORY TESTS Anemia may be marked Mean cell volume is normal or increased Peripheral blood smear may show macro-ovalocytes White blood cell count usually normal or reduced; neutropenia is common Neutrophils may exhibit morphologic abnormalities, including deficient numbers of granules, or bilobed nucleus (Pelger-Huet anomaly) Myeloid series may be left shifted with small numbers of promyelocytes or blasts Platelet count is normal or reduced; hypogranular platelets may be present

13 IMAGING STUDIES Radiographic findings are variable Stage I: hilar adenopathy alone Stage II: hilar adenopathy with parenchymal involvement Stage III: parenchymal involvement alone Parenchymal involvement usually manifests as diffuse reticular infiltrates, but focal infiltrates, acinar shadows, nodules, and rare cavitation are seen Pleural effusion occurs in < 10% of patients

14 DIAGNOSTIC PROCEDURES ECG may show conduction disturbances and dysrhythmias Biopsy demonstrating noncaseating granulomas is required for diagnosis Easily accessible biopsy sites include lymph nodes, skin lesions, and salivary glands

15 DIAGNOSTIC PROCEDURES Bone marrow aspirate and biopsy are characteristically hypercellular, but it may be hypocellular Signs of abnormal erythropoiesis include Megaloblastic features Nuclear budding Multinucleated erythroid precursors

16 DIAGNOSTIC PROCEDURES Prussian blue stain may demonstrate ringed sideroblasts Myeloid series is often left shifted with variable increases in blasts Deficient or abnormal myeloid granules may be seen A characteristic abnormality is dwarf megakaryocytes with unilobed nucleus Cytogenetics may be abnormal

17 Treatment MEDICATIONS Erythropoietin, 30,000 units subcutaneously weekly, reduces red blood cell transfusion requirement in 20% The combination of high-dose erythropoietin and myeloid growth factors produces higher response rate, but the cost is very high

18 MEDICATIONS Oral deferasirox (20 mg/kg/d) Used as iron chelation therapy Prevents serious iron overload in patients who depend on red blood cell transfusion and who do not have immediately life-threatening disease

19 Lenalidomide Recommended initial dose is 10 mg orally daily Approved for treatment of transfusiondependent anemia due to myelodysplasia Effective in patients with the 5q-cytogenetic abnormality Most common side effects are neutropenia and thrombocytopenia, but venous thrombosis is also seen and warrants aspirin prophylaxis Cost is extremely high, and it is not effective either for cell lines other than red blood cells or for patients with increased blasts

20 MEDICATIONS Patients affected primarily with severe neutropenia may benefit from the use of myeloid growth factors such as G-CSF Azacitidine improves both symptoms and blood counts and prolongs survival and time to conversion to acute leukemia Decitabine can produce similar responses

21 THERAPEUTIC PROCEDURES Red blood cell transfusions are indicated for severe anemia Allogeneic stem cell transplantation Only curative therapy for myelodysplasia Role is limited by advanced age of many patients and indolent course of disease

22 Outcome COMPLICATIONS Infection and bleeding

23 PROGNOSIS Myelodysplasia is ultimately fatal, most commonly because of infections or bleeding Risk of transformation to AML depends on the percentage of blasts in bone marrow Patients with refractory anemia without excess blasts may survive many years, with low risk of leukemia (< 10%) Patients with excess blasts or CMML have short survivals (usually < 2 years) and higher (20 50%) risk of developing acute leukemia

24 PROGNOSIS Deletions of chromosomes 5 and 7 associated with poor prognosis Cure rates of allogeneic transplantation are 30 60%, depending on risk status of disease

25 WHEN TO REFER All patients should be referred to a hematologist WHEN TO ADMIT Hospitalization is needed only for specific complications, such as severe infection

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