Blood/Blood Cells and Cellular Components ›› Neutrophils ›› Abnormal
Metamyelocyte
›Microscopic Features:
- 2-3x larger than a mature RBC
- Intermediate nuclear to cytoplasmic ratio (more cytoplasm than promyelocyte)
- Kidney bean shaped Nucleus with nucleus indentation (less than 1/2 the diameter) and mature chromatin (clumped)
- Perinuclear clearing is common
- Nucleoli are absent
- More cytoplasm with only secondary granules
- Secondary (specific) granules of neutrophilic (lilac), eosinophilic (red-orange), or basophilic (blue) color are present based on precursor type
›Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
- PB: None
- BM: ~15%
- LN: None
›May Resemble:
›Differential Diagnoses:
If in blood or increased numbers in bone marrow:
Chronic Myelogenous Leukemia (CML)
Leukemoid reaction
Post GCSF therapy
Chronic Neutrophilic Leukemia
Chronic Myelogenous Leukemia (CML)
Leukemoid reaction
Post GCSF therapy
Chronic Neutrophilic Leukemia
›Classic Immunophenotype:
- CD34-
- CD117-
- HLA-DR-
- CD13+
- CD33+
- CD15+
- CD11b+
- CD16+
- MPO+
›Cartoon Image:
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for direct comparison
for direct comparison
›Misc:
Maturation step that comes after myelocyte and preceeds the band neutrophil