Images of peripheral blood smears with pyknocytes present. Pyknocytes are indicated by the arrows. 100x oil immersion. From MLS Collection, University of Alberta.

Image 1: https://doi.org/10.7939/R33B5WQ09

Image 2: https://doi.org/10.7939/R3VX06J4H

Image 3: https://doi.org/10.7939/R3KS6JM01

Cell Description:

Pyknocytes appear as small, dark, pyknotic RBCs that lack central pallor and have an irregular, non-spherical shape.

Cell Formation:

Pyknocytes are rare, but may form as a result of red blood cell dehydration or oxidative damage.

Associated Disease/Clinical States: (6 Mary Louise ch 6 pg 103)

Pyruvate Kinase Deficiency

Glucose-6-phosphate (G6PD) Deficiency

Acute and severe hemolytic anemias

Infantile pyknocytosis

References:

1. Turgeon ML. Normal erythrocyte lifecycle and physiology.  In: Clinical hematology: theory and procedures. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1999. p. 103.