Size. Fifteen to 21 microns in diameter.
(2) Nucleus. The nucleus is round or ovoid with coarse-clumping, purple
chromatin material. One to three oval, light-blue nucleoli are usually present. The
nucleoli are less distinct than in the myeloblast. This cell has a nucleus-cytoplasm ratio
(3) Cytoplasm. The cytoplasm is light purple and contains varying numbers
and sizes of dark nonspecific granules that stain red to purplish-blue. The granules
usually overlie the nucleus.
Figure 4-3b. Granulocytic series:
b. Promyelocyte with Auer Body.
c. Myelocyte. In the myelocytic stage the granules are definite and so
numerous that frequently they obscure nuclear detail. While promyelocytes are
sometimes distinguished as neutrophilic, eosinophilic, or basophilic, the differentiation is
generally considered as first occurring in the myelocytic stage.
Figure 4-3c. Granulocytic series: Myelocyte.