The most immature progenitor cell with the morphological features of the thrombocytic lineage and the first morphologically recognizable cell of the same lineage. Large oval or round in shape.
Size:
21-50 µm.
Cytoplasm:
Abundant (nucleocytoplasmatic ratio is 0.5-0.6), basophilic in color; no granules.
Nucleus:
Irregular, oval or kidney-shaped, eccentrically laid; chromatin is arranged in a network and clusters.
