the presence of unusually thin or flattened red blood cells that when stained show a dark center and a peripheral ring of hemoglobin, separated by a pale unstained ring containing less hemoglobin, resulting in a bull's-eye appearance and resembling a 3D sombrero when viewed under EM; seen in certain anemias, thalassemias, hemoglobinopathies, obstructive jaundice, and the post-splenectomy state
macrocytosis
microcytosis
poikilocytosis +
polychromatophilia
spherocytosis
stomatocytosis
Synonyms
Exact Synonyms:
Mexican hat erythrocytes
;
increased Mexican hat cell number
;
increased codocyte number
;
increased target cell number
;
target erythrocytes
;
wafer-thin erythrocytes