89 MDS: Dyserythropoiesis, Dysmyelopoiesis & Dysmegakaryopoiesis

Michelle To and Valentin Villatoro

As previously discussed, MDS is a clonal disorder that results in defective cell maturation and results in dysplastic changes. The dysplasia can be seen in both the peripheral blood and in the bone marrow. Dysplasia may be seen in one or more cell lines, and the types of dysplasia seen vary. Below are descriptions that may be seen, organized by cell lineage.


Dyserythropoiesis

Affected Cell line: Erythroids.1-3

 

Table 1. Dysplastic features found in MDS erythrocytes in the peripheral blood and bone marrow.1-3

PBS:

Dimorphic Population

Oval-macrocytes

Hypochromic/Microcytic RBCs (with normal iron stores)

Basophilic stippling

Howell-Jolly bodies

Siderocytes

Decreased polychromasia

BM:

Multiple Nuclei

Abnormal Nuclear shapes (budding, lobes, fragmentation, bridging)

Megaloblastoid features

Vacuolization

Ringed Sideroblasts

Abnormal staining of the cytoplasm (due to basophilic stippling and hemoglobin)


Dysmyelopoiesis/Dysgranulopoiesis

Affected Cell line: Granulocytes.1-3

 

Table 2. Dysplastic features found in MDS granulocytes in the peripheral blood and bone marrow. 1-3

PBS:

Agranulation

Hypogranulation

Abnormal nuclear shapes (hypersegmentaion, hyposegmentation, ring-shaped nuclei)

Left shift

Monocytosis

Neutropenia

Increased Blasts

BM:

Nuclear-cytoplasmic asynchrony

Abnormal cytoplasmic staining

Abnormal granulation (hypogranulation, hypergranulation)

Increased Blasts

+/- Auer rods


Dysmegakaryopoiesis 

Affected Cell line: Megakaryoctyes and platelets.1-3

 

Table 3. Dysplastic features found in MDS megakaryocytes and platelets in the peripheral blood and bone marrow. 1-3

PBS:

Thrombocytopenia

Hypogranulation/Agranulation

Micromegakaryocytes

Giant PLTs

BM:

Magakaryocytes with multiple separated nuclei

Abnormal granulation (hypogranulation)

Large mononuclear megakaryocytes

Micromegakaryocytes

Micromegakaryoblasts

Other Tests:

Platelet function tests are abnormal


References:

1. Rodak BF. Myelodysplastic syndromes. In: Rodak’s hematology clinical applications and principles. 5th ed. St. Louis, Missouri: Saunders; 2015. p.591-603.

2. Lawrence LW, Taylor SA. Myelodysplastic syndromes. In: Clinical laboratory hematology. 3rd ed. New Jersey: Pearson; 2015. p. 479-99.

3. D’Angelo G, Mollica L, Hebert J, Busque L. Myelodysplastic syndromes. In: Clinical hematology and fundamentals of hemostasis. 5th ed. Philadelphia: F.A. Davis Company; 2009. p. 412-39.

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A Laboratory Guide to Clinical Hematology by Michelle To and Valentin Villatoro is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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