In the metamyelocyte stage, the cytoplasm and nucleus continue to decrease in size. The cytoplasm achieves full secondary granule content. The chromatin becomes more dense, knotted, and compact, while the nucleus begins to indent and acquire the familiar "kidney bean" shape.
By the end of the stage, the cell will be similar in size to a mature neutrophil with similarly cytoplasmic granularity.
The top image to the right shows a fairly classic metamyelocyte. Observe the indented kidney bean-shaped nucleus and neutrophil-colored cytoplasm. Notice the clumped aggregates of chromatin in each pole of the nucleus. The vacuolated cytoplasm in this cell is an indication of toxic stress.
In the bottom image to the right, notice the metamyelocytes (see red arrows) and their chromatin patterns. The patterns becomes more dense and clumped as the metamyelocytes continue to mature to the band neutrophil stages (see blue arrows).