Morphologic features in blood and bone marrow used in the diagnosis and classification of putative MDS
| Features . | Use in diagnosis and/or classification . |
|---|---|
| Blood counts (Hb, ANC, Plt) | Essential to document at least 1 cytopenia. Essential to document absence of thrombocytosis (Plt ≥450 × 109/L) that would tend to exclude MDS and suggest an MDS/MPN, except if meeting criteria for MDS with isolated del(5q). |
| WBC | Essential to document absence of persistent leukocytosis (WBC ≥13 × 109/L, not due to lymphocytosis) that would tend to exclude MDS and suggest an MDS/MPN. |
| Monocytes in blood | Essential to document absence of persistent monocytosis (≥0.5 × 109/L and ≥10% of WBC) that would tend to exclude MDS and suggest CMML. |
| Blasts in blood and marrow | Blast percentage of nucleated cells essential to classify MDS and exclude AML (if blasts are ≥20%), optimally counting at least 500 cells in the bone marrow aspirate smear or touch preparation and 200 cells in blood. Blast estimation by CD34 staining of the bone marrow biopsy may substitute if the aspirate is hemodilute or unobtainable. |
| Auer rods | Essential to document, if present, for classification. |
| Megakaryocyte dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in both aspirate smear and biopsy; at least 25 megakaryocytes should be evaluated. |
| Erythroid dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in aspirate smear. |
| Granulocytic dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in aspirate and blood smears. |
| Ring sideroblasts | Essential to evaluate and quantify (% of mature erythroid precursors) in an iron-stained aspirate smear. |
| Bone marrow cellularity | Essential to evaluate and quantify as percentage of marrow space in biopsy specimen for WHO5 classification. |
| Bone marrow fibrosis | Essential to evaluate and quantify (MF grade 0-3) in reticulin-stained biopsy specimen for WHO5 classification. |
| Features . | Use in diagnosis and/or classification . |
|---|---|
| Blood counts (Hb, ANC, Plt) | Essential to document at least 1 cytopenia. Essential to document absence of thrombocytosis (Plt ≥450 × 109/L) that would tend to exclude MDS and suggest an MDS/MPN, except if meeting criteria for MDS with isolated del(5q). |
| WBC | Essential to document absence of persistent leukocytosis (WBC ≥13 × 109/L, not due to lymphocytosis) that would tend to exclude MDS and suggest an MDS/MPN. |
| Monocytes in blood | Essential to document absence of persistent monocytosis (≥0.5 × 109/L and ≥10% of WBC) that would tend to exclude MDS and suggest CMML. |
| Blasts in blood and marrow | Blast percentage of nucleated cells essential to classify MDS and exclude AML (if blasts are ≥20%), optimally counting at least 500 cells in the bone marrow aspirate smear or touch preparation and 200 cells in blood. Blast estimation by CD34 staining of the bone marrow biopsy may substitute if the aspirate is hemodilute or unobtainable. |
| Auer rods | Essential to document, if present, for classification. |
| Megakaryocyte dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in both aspirate smear and biopsy; at least 25 megakaryocytes should be evaluated. |
| Erythroid dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in aspirate smear. |
| Granulocytic dysplasia | Essential to document and quantify (≥10%, present but <10%, or absent) in aspirate and blood smears. |
| Ring sideroblasts | Essential to evaluate and quantify (% of mature erythroid precursors) in an iron-stained aspirate smear. |
| Bone marrow cellularity | Essential to evaluate and quantify as percentage of marrow space in biopsy specimen for WHO5 classification. |
| Bone marrow fibrosis | Essential to evaluate and quantify (MF grade 0-3) in reticulin-stained biopsy specimen for WHO5 classification. |
ANC, absolute neutrophil count; Hb, hemoglobin; MPN, myeloproliferative neoplasm; MF, myelofibrosis; Plt, platelet count; WBC, white blood cell count.