CHAPTER 16: EXAMINATION OF THE PERIPHERAL BLOOD FILM AND CORRELATION WITH THE COMPLETE BLOOD COUNT

Question 1

(1) A laboratory science student consistently makes wedge technique blood films that are too long and thin. What change in technique would improve the films?

a. Increasing the downward pressure on the pusher slide
b. Decreasing the acute angle of the pusher slide
c. Placing the drop of blood closer to the center of the slide
d. Increasing the acute angle of the pusher slide

Answer 1

d. Increasing the acute angle of the pusher slide

Question 2

(2) When a blood film is viewed through the microscope, the RBCs appear redder than normal, the neutrophils are barely visible, and the eosinophils are bright orange. What is the most likely cause?

a. The slide was overstained.
b. The stain was too alkaline.
c. The buffer was too acidic.
d. The slide was not rinsed adequately.

Answer 2

c. The buffer was too acidic.

Question 3

(3) A stained blood film is held up to the light and observed to be bluer than normal. What microscopic abnormality might be expected on this film?

a. Rouleaux
b. Spherocytosis
c. Reactive lymphocytosis
d. Toxic granulation

Answer 3

a. Rouleaux

Question 4

(4) A laboratorian using the 40x objective lens sees the following numbers of WBCs in 10 fields: 8, 4, 7, 5, 4, 7, 8, 6, 4, 6.
Which of the following WBC counts most closely correlates with the estimate?

a. 1.5 x 10^9/L
b. 5.9 x 10^9/L
c. 11.8 x 10^9/L
d. 24 x 10^9/L

Answer 4

c. 11.8 x 10^9/L

Question 5

(5) A blood film for a very anemic patient with an RBC count
of 1.25 x 10^12/L shows an average of seven platelets per oil
immersion field. Which of the following values most closely
correlates with the estimate per microliter?

a. 14,000
b. 44,000
c. 140,000
d. 280,000

Answer 5

b. 44,000

Question 6

(6) A blood film for a patient with a normal RBC count has an average of 10 platelets per oil immersion field. Which of the following values best correlates with the estimate per microliter?

a. 20,000
b. 100,000
c. 200,000
d. 400,000

Answer 6

c. 200,000

Question 7

(7) What is the absolute count (x 10^9/L) for the lymphocytes if the total WBC count is 9.5 x 10^9/L and there are 37% lymphocytes?

a. 3.5
b. 6.5
c. 13
d. 37

Answer 7

a. 3.5

Question 8

(8) Which of the following blood film findings indicates EDTA-induced pseudothrombocytopenia?

a. The platelets are pushed to the feathered end.
b. The platelets are adhering to WBCs.
c. No platelets at all are seen on the film.
d. The slide has a bluish discoloration when examined macroscopically

Answer 8

b. The platelets are adhering to WBCs.

Question 9

(9) Which of the following is the best area to review or perform a differential on a stained blood film?

a. Red blood cells are all overlapped in groups of three or more.
b. Red blood cells are mostly separated, with a few overlapping.
c. Red blood cells look flattened, with none touching.
d. Red blood cells are separated and holes appear among the cells.

Answer 9

b. Red blood cells are mostly separated, with a few overlapping.

Question 10

(10) Given the following data, summarize the following blood picture:

WBC: 86.3 x 10^9/L
HGB: 9.7 g/dL
HCT: 24.2%
MCV: 87.8 fL
MCHC: 33.5%
PLT: 106 x 10^9/L

a. Leukocytosis, normocytic-normochromic anemia, thrombocytopenia
b. Microcytic-hypochromic anemia, thrombocytopenia
c. Neutrophilia, macrocytic anemia, thrombocytosis
d. Leukocytosis, thrombocytopenia

Answer 10

a. Leukocytosis, normocytic-normochromic anemia, thrombocytopenia