Interpreting FBC

Question 1

Causes of increased mean cell volume (MCV)?

Answer 1

Megaloblastic anaemia (B12, folate)
Liver disease
Alcohol, smoking
Haemolytic anaemia
Hypothyroidism
Drugs
Myelodysplasia
Myeloma

Question 2

Causes of decreased mean cell volume (MCV)?

Answer 2

Iron deficiency anaemia
Thalassaemia
Anaemia of chronic disease

Question 3

Red cell distribution width (RDW)

Answer 3

The variation in the size of the RBC

-> increased RDW = increased variation

Question 4

Anisocytosis

Answer 4

Increased variation in size of RBC (increased RDW)

Question 5

How can RDW be used?

Answer 5

Asses the cause or timeline of anaemia
Eg RDW increased in developing or recently treated iron deficiency
RDW increased is normal is thalassaemia trait
RDW increased during haemolysis due to presence of reticulocytes

Question 6

Mean cell haemoglobin (MCH)

Answer 6

Average measure of the amount of Hb in each RBC.

Used in assessment of anaemia

Question 7

Why would MCH be: reduced? Raised? Normal?

Answer 7

Reduced - iron deficiency, thalassaemia, haemoglobinopathy
Raised - macrocytic anaemias
Normal - mixed deficiency

Question 8

Reticulocyte count

Answer 8

Measurement of number of young erythrocytes

Question 9

Reasons for increased reticulocyte count?

Answer 9

Haemolytic anaemia
Recent blood loss
Response to iron, vit B12, folate replacement
Response to EPO
Recovery from bone marrow suppression

Question 10

Reasons for decreased reticulocyte count?

Answer 10

Haematinic deficiency
Bone marrow failure
Parvovirus infection

Question 11

Dimorphism

Answer 11

Two distinct populations of RBC (post transfusion)

Question 12

Polychromatic

Answer 12

Two different stainings in blood film - reticulocytes

Question 13

Poikilocytosis

Answer 13

Abnormally shaped RBC

Question 14

Spherocytosis

Answer 14

Spherical RBC

Question 15

Elliptocytosis

Answer 15

Elliptical RBC

Question 16

Irregularly contracted calls

Answer 16

Small dense RBC but not as regular in shape as spherocytes

Question 17

Echinocytes

Answer 17

Spiculated cells

Question 18

Acanthocytes

Answer 18

Spiculated cells

Question 19

Keratocytes

Answer 19

Spiculated cells

Question 20

Schistocytes

Answer 20

Red cell fragments

Question 21

Sickle cells

Answer 21

Crescent or sickle shaped cells seen in sickle cell disease

Question 22

Target cells

Answer 22

RBC with dark area in middle of the area of central pallor

Question 23

Blister cells

Answer 23

Empty pocket at the edge of the red cell, consistent with oxidative haemolysis/G6PDH deficiency

Question 24

Howell Jolly bodies

Answer 24

DNA/nuclear fragments

Question 25

Basophilic stippling

Answer 25

RNA inclusions

Question 26

Pappenheimer bodies

Answer 26

Iron inclusions (Perl’s stain)

Question 27

Heinz bodies

Answer 27

Denatured Hb (aggregates)

Question 28

Haemoglobin H inclusions

Answer 28

“Golf-ball cells” - beta chain tetramers found in severe alpha thalassaemia (Brilliant cresyl blue) - ?

Question 29

What abnormality may be present in the blood film of a patient with G6PDH deficiency? (There are two)

Answer 29

Blister cells Heinz bodies

Question 30

Pencil cells

Answer 30

Pencil shaped cells (elliptocytes)

Question 31

What expected results would you get from iron deficiency?

Answer 31

Decreased Hb, MCV, MCH, MCHC Increased RDW Low or normal reticulocyte count Cells present in blood include hypochromic, microcytic, pencil cells, a few target cells

Question 32

What expected results would you get from vit B12/folate deficiency?

Answer 32

Decreased HB, RCC, Hct (haematocrit) Increased RDW, MCH, MCV Low or normal reticulocyte count Cells present in blood include oval macrocytes, hypersegmented neutrophils, teardrop cells

Question 33

Causes of macrocytosis

Answer 33

Alcohol/smoking Drugs interfering with DNA synthesis (methotrexate) Bone marrow failure conditions

Question 34

What expected results would you get from haemolysis?

Answer 34

Decreased or normal Hb Increased or normal MCV Increased RDW Normal MCH Elevated reticulocyte count Cells present in blood include spherocytes, schistocytes, polychromasia