Myelodysplastic Syndromes (MDS) Flashcards Preview

SBL Exam 1 WBCs, Spleen, and Thymus > Myelodysplastic Syndromes (MDS) > Flashcards

Flashcards in Myelodysplastic Syndromes (MDS) Deck (5)
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What are myelodysplastic syndromes?

-dysplasia of myeloid cells

-bone marrow is hypercellular as poorly differentiated cells fail to enter periphery 

-myeloblasts <20% prevalence in bone marrow (as opposed to >20% in AML)

-results in peripheral cytopenias


*10-40% progress to AML*


What are the classifications of MDS?

-refractory anemia (RA): <5% myeloblasts, abnormal RBC precursors

-refractory anemia with ring sideroblasts (RARS): <5% myeloblasts w/ >15% of RBC precursors as ring sideroblasts

-refractory anemia with excess blasts (RAEB): 5-19% myeloblasts

-refractory anemia with excess blasts in transformation (RAEB-T): 5-19% myeloblasts

-chronic myelomonocytic leukemia (CMML): <20% myeloblasts w/ 1x109 monocytes in peripheral blood


*all must be <20% otherwise they are classified as AML instead*


What is the common presentation of MDS?

-primarily older adults (mean age 70)

-50% asymptomatic

-when symptomatic,  related to pancytopenia (weakness, infection, and hemorrhage)


What are possible histologic features of MDS?

-ring sideroblasts: erythroblasts with iron-laden mitochondira

-pseudo-Pleger-Hüet cells: neutrophils with only two lobes

-pawn ball megakaryocytes: megakaryocytes with single unlobulated nuclei or with multiple nuclei


What is the course/prognosis of MDS?

-somewhat aggressive course, worse in t-MDS


-variable prognosis (median survival 9-29 mo), improves with younger age

-10-40% progress to AML