Myeloblast- The first recognizable cell in the granulocytic series. Using light microscopy, they are virtually identical for proerythroblasts. Round nucleus with fine chromatin and one or more nucleoli. The cytoplasma stains blue but no granules are present.
Promyelocyte- Large (15-18u), mitotic cell with nonspecific azuro philic granules in basophilic cytoplasm. Spherical nucleus with fewer nucleoli and coarser chromatin.
*Myelocyte- Abundant (12-15%) highly mitotic, variable size (12-20u), less basophilic cytoplasm with many specific granules. Dense, large, ovoid, eccentric nucleus with noticeable indentation and Golgi (perinuclear clear space)(arrow).