Description:

The most immature precursor with morphologic features of monocytic lineage and the first morphologically recognizable cell of the monocytic lineage, round or oval shape.
Monoblast is in structure very similar to the myeloblast from which it cannot be distinguished on morphological grounds alone, even by means of the electronic microscope. They can be differentiated using cytochemical methods.

Size:

³20 µm.

Cytoplasm:

Blue or greyish and no granules.

Nucleus:

Large, round or slightly indented, and the chromatin is very fine and indistinct.

Nucleoli:

1-2 nucleoli.