4-13. MEGAKARYOCYTIC SERIES
Twenty to 50 microns in diameter.
(2) Nucleus. One to two large oval or kidney-shaped nuclei are present.
There is a fine chromatin pattern. Multiple nucleoli may be present which stain blue.
The nucleus cytoplasm ratio is approximately 10:1.
(3) Cytoplasm. The cytoplasm is blue, nongranular, and may have small,
blunt pseudopods. It is usually seen as a narrow band around the nucleus.
Figure 4-8a. Megakaryocytic series:
Megakaryoblast: Bone marrow.
Size. Twenty to 50 microns in diameter.
(2) Nucleus. One-to-two indented round or oval nuclei are present. They
may show slight lobulation. The nuclear chromatin is purple, coarse, and granular.
Multiple nuclei are present but may be indistinct.
Size. Forty to 100 microns in diameter.
(2) Nucleus. Two-to-sixteen nuclei may be visible or the nucleus may show
multilobulation. No nucleoli are visible. The nuclear chromatin is purple, coarse, and
(3) Cytoplasm. The cytoplasm is pinkish-blue in color and very granular.
Numerous blue-purple granules begin to aggregate into small bundles that bud off from
the cell to become platelets.