I.B.001

Basophilic stippling. Blood film. The arrow denotes a red cell with numerous, scattered prominent blue inclusions identified with a polychrome stain. Basophilic stippling may be present in a variety of conditions such as clonal sideroblastic anemia, polyclonal sideroblastic anemia, megaloblastic anemia, thalassemia, and others. It is particularly useful in distinguishing iron deficient erythropoiesis from thalassemia minor since it is absent in the former and present in the latter. It is also a marker of red cell dysmorphia in clonal anemia.

I.B.002

Basophilic stippling. Blood films. (A) Red cell with fine basophilic stippling at center top of field in patient with beta-thalassemia minor. (B) Red cell with coarse basophilic stippling in sideroblastic anemia. Basophilic stippling is a very important marker of disordered erythropoiesis seen notably in thalassemia and sideroblastic and megaloblastic anemia as well as other erythroid disorders. It is not present in iron deficiency anemia and helps in distinguishing that hypochromic-microcytic anemia from thalassemia minor in which careful examination of the blood film will usually permit identification of stippled red cells.

I.B.003

Cabot ring. Blood film. Rarely seen. Red to purple colored ring forms in red cells. Significance uncertain.

I.B.004

Cabot Ring. Note ringed inclusion in red cell in center of the field. Cabot rings are red-purple staining threadlike structures in the shape of a ring. Their origin has not been established. They may be seen in anemia, notably megaloblastic anemia.