Self Instructional Manual for Cancer Registrars - SEER - National ...

Granulocytes or granular leukocytes can be further subdivided (based on the staining properties
of the granules) into:
Neutrophils (purple) - 40-60% of all leukocytes
Eosinophils (red) - 1-3% of all leukocytes
Basophils (blue) - 0-1% of all leukocytes
A neutrophil may be further specified as segmented (SEOS), banded (STABS), or juvenile (a
metamyelocyte).
A myelocyte is a granulocytic cell.
Agranular leukocytes may be further subdivided into two types:
Monocytes - 4-8% of all leukocytes
Lymphocytes - 20-40% of all leukocytes
DEVELOPMENT OF WHITE BLOOD CELLS
Stem
Cell
Lymphoblast Myeloblast Monoblast
f I I
Prolymphocyte Promyelocyte Promonocyte
I I I
Lymphocyte Myelocyte Monocyte
I
Metamyeloc3,te
I
Granulocyte
Platelets
Platelets (thrombocytes) are tiny cells or discs whose primary function is hemostasis (clotting of
blood).
On the next page is a table of normal blood values. Compare the definitions above with the
terms and their values in the table.
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