RBC Morphology

Question 1

What term is used to describe variations in RBC size? What do we compare RBCs to to determine whether they are too big, too small, or just right?

Answer 1

Anisocytosis. RBC size is compared to the nucleus of a small lymphocyte.

Question 2

What is a term for RBCs that are too small? When is this seen?

Answer 2

Microcytic. Seen in thalessemias and iron deficiency anemia

Question 3

What is a term for RBCs that are too big? When is this seen?

Answer 3

Macrocytic Commonly seen in megaloblastic anemias (B12 or folate deficiency).

Question 4

What term is used to describe variations in RBC shape?

Answer 4

Poikilocytosis

Question 5

Answer 5

Spherocyte

Seen in hereditary spherocytosis and immune hemolytic anemias

Question 6

Answer 6

Burr cell

Seen in uremia

Question 7

Answer 7

Elliptocyte

Seen in hereditary elliptocytosis

Question 8

Answer 8

Schistocyte aka fragments

Seen in microangiopathies such as hemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura (TTP), or disseminated intravascular coagulation (DIC) or in traumatic hemolytic anemias (such as when RBCs are damaged by a malfunctioning heart valve)

Question 9

Answer 9

Sickle cells

Seen in sickle cell anemia

Question 10

Answer 10

Stomatocyte

Seen in liver disease or hereditary stomatocytosis

Question 11

Answer 11

Target cell

Seen in liver disease, hemoglobinopathies, or post-splenectomy

Question 12

Answer 12

Teardrop cell

Seen in myelofibrosis or extramedullary hemopoiesis

Question 13

Answer 13

Heinz bodies in an RBC (using a special stain)

They are hemoglobin precipitates seen in G6PD and some thalassemias

Question 14

Answer 14

Malaria in an RBC