Target cells (ie. codocytes) are sometimes found on peripheral smear in patients with advanced liver disease. The bull’s-eye appearance is due to either 1) increased surface area of the cell membrane, as in liver disease, or 2) decreased surface area of the hemoglobin within, as in thalassemia or severe iron deficiency anemia.
The presence of a target cell may suggest that the stage of liver fibrosis is advanced. One should also consider the target cell’s relationship to the spleen. In the case of splenectomy, or perhaps an engorged/infarcted spleen with compromised macrophage functionality, there is an inability to clear deformed or damaged erythrocytes.