RBC Morphology

Question 1

Macrocytes

Answer 1

Larger than 8 um diameter
MCV > 100

Megaloblastic anemia, liver disease, accelerated erythropoiesis, newborns

Question 2

Microcytes

Answer 2

< 6 um diameter, MCV < 80

Iron deficiency, thalassemia, sideoblastic anemia, anemia of chronic disease

Question 3

Anisocytosis

Answer 3

Variation in RBC size
Related to RDW (RBC distribution width)

Post-transfusion, 2 deficiencies at once, idiopathic sideroblastic anemia

Question 4

Poikilocytosis

Answer 4

Variation in shape

Question 5

Echinocytes

Answer 5

Evenly spaced round projections

Liver disease, uremia, heparin therapy, pyruvate kinase deficiency, artifact

Question 6

Acanthocytes

Answer 6

Unevenly spaced pointed projections, lack central pallor
Excessive cholesterol in membrane

Alcoholic liver disease, post-splenectomy, abetalipoproteinemia

Question 7

Target cells

Answer 7

Liver disease, hemoglobinopathies, thalassemia, iron deficiency

Question 8

Spherocytes

Answer 8

No central pallor, MCHC May be > 37% (osmotic fragility)

Hereditary spherocytosis, G6PD deficiency, immune hemolytic anemias, burns (microspherocytes)

Question 9

Teardrops

Answer 9

Megaloblastic anemia, thalassemia, extramedullary hematopoiesis

Question 10

Sickle cells

Answer 10

Hemoglobin S

Hemoglobinopathies SS, SC, SD, and S/beta-thalassemia

Question 11

Helmet cells

Answer 11

Microangiopathic hemolytic anemias

Question 12

Schistocytes

Answer 12

Microangiopathic hemolytic anemias, burns, renal transplant rejection, G6PD deficiency

Question 13

Stomatocytes

Answer 13

Liver disease, hereditary stomatocytosis, artifact

Question 14

Elliptocytes

Answer 14

Hereditary elliptocytosis, iron deficiency, megaloblastic anemia, thalassemia major

Question 15

nRBC’s

Answer 15

Bone marrow stimulation/increased erythropoiesis
Shouldn’t be any on healthy patient smear

Thalassemia major, sickle cell anemia, hemolytic anemias, erythroleukemia, myeloproliferative disorders, a few in newborns

Question 16

Howell-Jolly bodies

Answer 16

DNA fragments (one per cell usually)

Sickle cell anemia, beta-thalassemia major, hemolytic anemia, megaloblastic anemia, alcoholism, post-splenectomy

Question 17

Basophilic stippling

Answer 17

RNA remnants, evenly dispersed

Thalassemia, megaloblastic anemias, soderoblastic anemia, lead poisoning, alcoholism

Question 18

Pappenheimer bodies

Answer 18

Iron granules clumped together at periphery of cell
Stain with Prussian blue

Sideroblastic anemia, hemoglobinopathies, thalassemia, megaloblastic anemia, myelodysplastic syndrome

Question 19

Cabot rings

Answer 19

Ring like structures (loops or figure 8), made of fragmented nuclear material

Megaloblastic anemia, myelodysplastic syndromes, lead poisoning

Question 20

Heinz bodies

Answer 20

Not seen with Wright stain, use supravital, denatured hemoglobin

G6PD deficiency, beta-thalassemia major, Hgb H disease, unstable hemoglobinopathies, drug-induced anemias