Basophilic stippling is the presence on a Wright-stained peripheral blood smear of relatively evenly distributed dark-blue particles or granules of varying size in the cytoplasm of erythrocytes. These dark-blue or blue-purple granules are predominantly sediments of ribosomes (RNA) and may indicate impaired hemoglobin synthesis, probably due to the instability of RNA in the young cell. The erythrocyte containing these inclusions may stain generally in other respects or be polychromatophilic.
Clinically significant basophilic stippling is referred to as coarse stippling. Fine stippling is often noted in polychromatophilic red cells and sometimes in other red cells and is generally insignificant. Fine stippling is considered artifactual and occurs during the drying of the red cells during slide preparation.
Coarse basophilic stippling may be seen in lead poisoning (or other heavy metal poisoning), thalassemias, and anemias associated with abnormal heme synthesis, such as sideroblastic anemia.
