Polychromatophilic Cells

By William Aird

Polychromatophilic cell (arrow) characterized by larger size than surrounding mature red cells and a purple-blue stained cytoplasm; P, platelet 100x (oil).
Peripheral smear from a 25-year-old woman with GI bleed shows multiple polychromatophilic red cells (polychromatophilia) 100x (oil).
Red blood cellPolychromatophilic cell
DefinitionImmature non-nucleated red cells with a blue hue in their cytoplasm; the blue may be barely visible or may be marked. Polychromatic red cells are typically larger than normal red cells. They tend to lack central pallor. When stained with supravital dyes the remaining mRNA and ribosomes give the red cells a “reticular” mesh-like network, hence the name “reticulocyte”. Of note, not all reticulocytes are recognized as polychromatophils on the Wright-giemsa stain.
Conditions associated with increased numbersHemolysis, bleeding, administration of erythropoietin
Mechanism of formationPart of normal process of erythropoiesis. Anucleate red cell that still contains RNA, ribosomes and other cytoplasmic organelles. Develops into a mature (pink-stained) red cell in the bone marrow and circulation.
Source/AuthorWilliam Aird
Reviewed and edited byParul Bhargava