Required section · Section 2 of 6
Build the cell call from several features
Read a Wright- or Wright-Giemsa-stained peripheral smear under oil immersion in the monolayer zone, where red cells are mostly touching in one layer without excessive overlap. Identify a cell from a pattern rather than one color or one nuclear shape. Compare size with nearby red cells, then assess chromatin, nucleus contour, cytoplasm, and granules. A normal mature neutrophil is roughly 12 to 15 micrometers with three to five nuclear lobes, pale cytoplasm, and fine inconspicuous granules.
A small mature lymphocyte is about red-cell size to slightly larger, with a round dense nucleus and only a thin light-blue cytoplasmic rim. A monocyte is usually the largest normal circulating leukocyte and has a folded or kidney-shaped nucleus, finer chromatin, and abundant gray-blue ground-glass cytoplasm. An eosinophil has a bilobed nucleus and prominent uniform orange-red granules. A basophil is uncommon and its coarse dark blue-purple granules may obscure an irregular nucleus.
A band neutrophil has a thick uninterrupted nuclear band rather than distinct lobes joined by filaments. Reporting bands separately versus combining them with segmented neutrophils follows local policy. Reactive-appearing lymphocytes are larger, variable lymphocytes with abundant basophilic cytoplasm and irregular borders; they are reported as morphology but still count within the total lymphocyte percentage.
| Cell type | Key nucleus feature | Cytoplasm or granules | Illustrative adult proportion |
|---|---|---|---|
| Neutrophil | 3 to 5 lobes | Pale, fine granules | 50 to 70% |
| Lymphocyte | Round, dense | Scant light-blue rim | 20 to 45% |
| Monocyte | Folded or kidney-shaped | Abundant gray-blue | 2 to 10% |
| Eosinophil | Bilobed | Large orange-red granules | 1 to 5% |
| Basophil | Irregular or S-shaped | Coarse dark granules | 0 to 1% |
Use the same feature sequence for every leukocyte before assigning a category.
Compare size
Use nearby red cells as a visual reference.
Read chromatin and nucleus
Assess density, lobulation, and contour.
Read cytoplasm and granules
Note amount, color, texture, and granule pattern.
Assign and continue
Record the best supported category, then move to the next field.
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