Blood/Blood Cells and Cellular Components ›› Neutrophils ›› Abnormal
Myeloblast
›Microscopic Features:
- 3-4x larger than a mature RBC
- High nuclear to cytoplasmic ratio
- Round Nucleus with immature chromatin (not clumped)
- Prominent nucleoli
- Cytoplasm is scant, gray to pale blue and lacks granules
›Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
- PB: None
- BM: 1-3%
- LN: None
›May Resemble:
›Differential Diagnoses:
If in blood or increased numbers in bone marrow:
Acute myeloid leukemia (AML)
Myelodysplastic Syndromes (e.g. RAEB-I or II)
Myeloproliferative Neoplasms (e.g. CML with increased blasts)
Leukemoid reactions
Post GCSF therapy
Acute myeloid leukemia (AML)
Myelodysplastic Syndromes (e.g. RAEB-I or II)
Myeloproliferative Neoplasms (e.g. CML with increased blasts)
Leukemoid reactions
Post GCSF therapy
›Classic Immunophenotype:
- CD34+
- CD117+
- HLA-DR+
- CD13+
- CD33+
- CD15-
- MPO+
›Cartoon Image:
Click and drag
for direct comparison
for direct comparison
›Misc:
Myeloblast with Auer rod is by definition abnormal and usually represents an underlying AML or high grade MDS (RAEB-II)