Immunohistochemistry in AML-NOS
AML with Minimal Differentiation (M0)
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MPO
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While negative by cytochemistry (by definition) a subset may have expression by flow cytometry or IHC.
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Most cases are Positive.
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~50% Positive (not a specific marker of lymphoblasts)
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~40% are Positive
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AML without maturation (M1)
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MPO
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Usually positive
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| CD34 |
~70% of cases are positive
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Often Positive
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| CD7 |
~30% of cases are positive
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10-20% of cases may show expression of CD2, CD4, CD19, and CD56.
AML with maturation (M2)
| CD34 |
Usually Positive, but may only be expressed on a subset of the blasts.
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| CD117 |
Usually Positive, but may only be expressed on a subset of the blasts.
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| CD7 |
~20-30% of cases are positive.
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Expression of CD4, CD2, CD19, or CD56 is not common (~10% of cases).
Acute Myelomonocytic Leukemia (M4)
| CD34 |
Usually Positive, but may only be expressed on a subset of the blasts (not in the monocytic derived cells).
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| CD117 |
Usually Positive, but may only be expressed on a subset of the blasts.
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| CD7 |
~30% of cases are positive.
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Acute Monoblastic and Monocytic Leukemia (M5)
| CD34 |
~30% of cases are positive (flow data)
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Usually Positive, more often than CD34. (flow data)
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| CD7 |
~25-40% of cases are positive. (flow data)
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~25-40% of cases are positive. (flow data)
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Acute Erythroid Leukemia (M6)
ERYTHROLEUKEMIA (erythroid/myeloid)
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May show abnormal dim expression in the erythroblasts.
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The myeloid population may excess myeloid markers similar to that of AMO with minimal maturation.
PURE ERYTHROID LEUKEMIA
| CD34 |
Usually negative
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| CD117 |
+/-
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Acute Megakaryoblastic Leukemia (M7)
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CD41
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Often Positive
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CD61
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Often Positive
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CD42
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Less often positive (more mature platelet marker)
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Usually Negative
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Usually Negative
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MPO
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Negative
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| TdT |
Negative
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| CD7 |
+/-
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Acute Panmyelosis with Myelofibrosis
| CD34 |
Usually Positive
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| CD117 |
Often Positive
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MPO
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Usually Negative
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