Quick Review Cards for Medical Laboratory Science

RBC Morphologycontinued Hematology Review 302

ABNORMALITY DESCRIPTION SIGNIFICANCE

Target cells (codocytes)

Stomatocytes

Spherocytes

Arrangement

Rouleaux

Agglutination

Bull’s-eye, “Mexican hat cell”

RBC with slit-like central pallor

Small, dark-staining RBCs without

central pallor

RBCs resemble stack of coins

RBCs in irregular clumps

Hemoglobinopathies, thalassemia, liver disease. May be

artifact if observed in only 1 part of smear.

Hereditary stomatocytosis, hereditary spherocytosis, tha-

lassemia, alcoholic cirrhosis, Rh null disease. May be artifact

in parts of smear that are too thin or too thick.

Membrane defect. Hereditary spherocytosis, autoantibodies,

burns, hemoglobinopathies, hemolysis, ABO HDN, incompat-

ible blood tf, tf of stored blood. A few are normal due to

aging of RBCs.

Serum protein abnormality; e.g., ↑globulins or fibrinogen.

Seen in multiple myeloma & macroglobulinemia. May be

artifact due to delay in spreading drop of blood or smear

that’s too thick.

Autoantibodies, cold autoagglutinin

DIC = disseminated intravascular coagulation
TTP = thrombotic thrombocytopenic purpura
HUS = hemolytic uremic syndrome