Primary Hematopoietic and Lymphoid Tissue ›› Bone Marrow ›› Myeloid ›› Granulocytes & Precursors ›› Basophilic ›› Abnormal
Basophils (increased)
›Microscopic Features:
- 2-3x larger than a mature RBC
- Low nuclear to cytoplasmic ratio (more cytoplasm than nucleus)
- Nucleus is mature and usually with 2-3 lobes connected by thin chromatin filament
- Nucleoli are absent
- More cytoplasm with only secondary granules
- Secondary (specific) granules are Basophilic (blue-violet) and obscure the underlying nucleus
›Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
- PB: Very Rare (5th most common WBC in blood, after neutrophils, lymphocytes, monocytes, and Eosinophils)
- BM: Rare scattered
- LN: None
›May Resemble:
- Eosinophil
- Segmented Neutrophil
- Pseudo-Pelger Huet Neutrophil
- Band Neutrophil
- Neutrophil with toxic granules
- Promyelocyte
- Mast Cell
›Differential Diagnoses:
Increased in:
CML accelerated phase
AML (rare variants)
Infection (e.g. varicella)
Hypersensitivity reactions (sometimes)
CML accelerated phase
AML (rare variants)
Infection (e.g. varicella)
Hypersensitivity reactions (sometimes)
›Classic Immunophenotype:
- CD45dim+
- Low SSC (Side light scatter)
- CD11b+
- CD13+
- CD16-
- CD15-
›Cartoon Image:
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›Misc:
Increased basophils may be associated with some myeloid neoplasms such as CML, or some infections or some hypersensitivity reactions