Myelodysplastic Syndromes

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The patient is 62 year old man who presents with increasing fatigue and bruising over several months. The patient is on no medications. CBC analysis shows: WBC 2.7 x10 9 /L; Neuts 1.1 x10 9 /L HGB 9.1 g/dL MCV 96 fl PLTS 47x10E9/L Cytogenetics: Normal Ring sideroblasts: − MDS − Alcohol/toxins − Drugs (e.g. INH) − Zinc toxicity − Copper deficiency − Pyridoxine deficiency − Congenital sideroblastic anemia − Mitochondrial cytopathy (Pearson syndrome) In this case, features suggest copper deficiency (in some cases due to zinc toxicity) RARS 9 year old girl presenting with fever and pancytopenia Hemophagocytic lymphohistiocytosis (HLH); dysplasia may be cytokine related 6
MDS cytogenetics Presumptive diagnosis in patients with persistent cytopenias of undetermined origin but lacking diagnostic morphologic dysplasia (should be followed for definitive dysplasia before unequivocal dx) *Alone NOT considered definitive evidence for MDS (in absence of dysplasia): +8 del(20q) Abnormality Frequency (diagnosis) Unbalanced -7 or del(7q) 10% (50% t-MDS) -5 or del(5q) 10% (40% t-MDS) +8* 10% del(20q)* 5-8% -Y* 5% i(17q) or t(17p) 3-5% del(11q) 3% del(12p) or t(12p) 3% -13 or del(13q) 3% del(9q) 1-2% idic(X)(q13) 1-2% Balanced t(11;16)(q23;p13.3) (3% t-MDS) t(3;21)(q26.2;q22.1) (2% t-MDS) t(1;3)(p36.3;q21.2) 1% t(2;11)(p21;q23) 1% inv(3)(q21;q26.2) 1% t(6;9)(p23;q34) 1% -Y WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, 2008. Flow Cytometry in MDS • Presently not routinely used for diagnosis or classification • Evaluation of previously diagnosed MDS by highly experienced flow labs with numerous myeloid markers and objective criteria for “abnormal” show: • Sensitivity: ~70-90% • Specificity: ~90% • ~10% flow abnormal with non-diagnostic morphology and cytogenetics – Insufficient data to determine whether these biologically behave like MDS (true or false pos?) FISH Analysis • Panels often include -5/del(5q), -7/del(7q), +8, and del(20q) • FISH correlates with karyotypic findings • FISH detects few (0-6%) additional abnormalities if karyotype is adequate and generally not needed in this setting • FISH useful if: – suboptimal metaphase analysis; detects up to 15% more abnormalities – morphology suggests a specific abnormality that was not detected by cytogenetics • Sensitivity for residual disease following treatment is not much better than routine karyotype Flow Cytometry in MDS Cautions • Reactive conditions (marrow recovery, G-CSF therapy, infection) can cause mild phenotypic alterations. • Insufficient literature to fully understand myeloid phenotypic change in reactive conditions that may mimic MDS • Blast assessment can be useful, but...morphologic blast count required for diagnosis and classification because: – Some blasts do not express stem cell antigens (CD34, CD117) – Processing for flow lyses erythroid precursors – Blasts can be fragile with a subset lost during processing 7
Page 1 and 2: Myelodysplastic Syndromes Joan E. E
Page 3 and 4: WHO MDS Classification • Dysplasi
Page 5: Neutrophil dysplasia • Hypo-, agr
Page 9 and 10: Hypocellular MDS • Proper classif
Page 11 and 12: Paryoxysmal Nocturnal Hemoglobinuri
Page 13 and 14: The patient is a 32 year old taxi d
Page 15: The patient is a 56 year old man wh

Myelodysplastic Syndromes

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