Page 62 - Clinical Hematology Atlas

46 SECTION TWO HEMATOPOIESIS

MYELOBLAST

A B
FIGURE 5–2A Myeloblast with no granules. FIGURE 5–2B Myeloblast with up to 20 granules.

Cytoplasm

Nucleoli

Nucleus
C
FIGURE 5–2C Schematic of Figure 5-2, A,
myeloblast.

SIZE: 15-20 mm
NUCLEUS: Round to oval
Nucleoli: 2-5
Chromatin: Fine D
CYTOPLASM: Moderate basophilia FIGURE 5–2D Electron micrograph of myeloblast
Granules: Absent or up to 20 (316,500).
N/C RATIO: 4:1
REFERENCE INTERVAL:
Bone Marrow: 0% to 2%
Peripheral Blood: 0%

Blasts without granulation are sometimes referred
to as Type I blasts and those with up to 20 granules
as Type II blasts, although they are generally not
separated as such in the differential count.