1.8 Hematology Problem-Solving

Question 1

A 19-year-old man came to the emergency department with severe joint pain, fatigue, cough, and fever. Review the following laboratory results:
WBCs 21.0 × 109/L
RBCs 3.23 × 1012/L
Hgb 9.6 g/dL
PLT 252 × 109/L
Differential: 17 band neutrophils; 75 segmented neutrophils; 5 lymphocytes; 2 monocytes; 1 eosinophil; 26 NRBCs
What is the corrected WBC count?
A. 8.1 × 109/L
B. 16.7 × 109/L
C. 21.0 × 109/L
D. 80.8 × 109/L

Answer 1

B. 16.7 × 109/L
(Total WBC × 100)/(Total Count+NRBC)

Question 2

A manual WBC count is performed. Eighty WBCs are counted in the four large corner squares of a Neubauer hemacytometer. The dilution is 1:100. What is the total WBC count?
A. 4.0 × 109/L
B. 8.0 × 109/L
C. 20.0 × 109/L
D. 200.0 × 109/L

Answer 2

C. 20.0 × 109/L
(# cells counted × 10 (depth factor) × dilution factor) ÷ area counted

Question 3

A manual RBC count is performed on pleural fluid. The RBC count in the large center square of the Neubauer hemacytometer is 125, and the dilution is 1:200. What is the total RBC count?
A. 27.8 × 109/L
B. 62.5 × 109/L
C. 125.0 × 109/L
D. 250.0 × 109/L

Answer 3

D. 250.0 × 109/L
(# cells counted × 10 (depth factor) × dilution factor) ÷ area counted

Question 4

Review the scatterplot of WBCs shown. Which section of the scatterplot denotes the
number of monocytes?
A. A
B. B
C. C
D. D

Answer 4

A. A
(top left)

Question 5

Review the following automated CBC values.
WBC = 17.5 × 109/L (flagged) MCV = 86.8 fL
RBC = 2.89 × 1012/L MCH = 28.0 pg
Hgb = 8.1 g/dL MCHC = 32.3%
Hct = 25.2% PLT = 217 × 109/L
Many sickle cells were observed on review of the peripheral blood smear. On the basis of this finding and the results provided, what automated parameter of this patient is most likely inaccurate, and what follow-up test should be done to accurately assess this parameter?
A. MCV/perform reticulocyte count
B. Hct/perform manual Hct
C. WBC/perform manual WBC count
D. Hgb/perform serum–saline replacement

Answer 5

C. WBC/perform manual WBC count

Question 6

Review the following CBC results for a 2-day-old infant:
WBC = 15.2 × 109/L MCV = 105 fL
RBC = 5.30 × 1012/L MCH = 34.0 pg
Hgb = 18.5 g/dL MCHC = 33.5%
Hct = 57.9% PLT = 213 × 109/L
These results indicate:
A. Macrocytic anemia
B. Microcytic anemia
C. Liver disease
D. Normal values for a 2-day-old infant

Answer 6

D. Normal values for a 2-day-old infant

Question 7

Review the following scatterplot, histograms, and automated values for a 21-year-old college student.
WBC differential: 5 band neutrophils; 27 segmented neutrophils; 60 atypical lymphocytes; 6 monocytes; 1 eosinophil; 1 basophil
What is the presumptive diagnosis?
A. Infectious mononucleosis
B. Monocytosis
C. CLL
D. β-Thalassemia

Answer 7

A. Infectious mononucleosis

Question 8

Review the following scatterplot, histograms, and automated values for a 61-year-old woman.
WBC differential: 14 band neutrophils; 50 segmented neutrophils; 7 lymphocytes; 4 monocytes; 10 metamyelocytes; 8 myelocytes; 1 promyelocyte; 3 eosinophils; 3 basophils; 2 NRBCs/100 WBCs
What is the presumptive diagnosis?
A. Leukemoid reaction
B. CML
C. AML
D. Megaloblastic leukemia

Answer 8

B. CML

Question 9

Review the automated results from the previous question. Which parameters can be released without further follow-up verification procedures?
A. WBC and relative percentages of WBC populations
B. RBCs and PLTs
C. Hgb and Hct
D. None of the automated counts can be released without follow-up verification

Answer 9

D. None of the automated counts can be released without follow-up verification

Question 10

Refer to the following scatterplot, histograms, and automated values for a 45-year-old man. What follow-up verification procedure is indicated before these results can be released?
A. Redraw blood sample using a sodium citrate tube; multiply PLTs × 1.11
B. Dilute WBCs 1:10; multiply × 10
C. Perform plasma blank Hgb to correct for lipemia
D. Warm specimen at 37°C for 15 minutes; rerun specimen

Answer 10

A. Redraw blood sample using a sodium citrate tube; multiply PLTs × 1.11

Question 11

Refer to the following scatterplot, histograms, and automated values for a 52-year-old woman. What follow-up verification procedure is indicated before these results can be released?
A. Redraw specimen using a sodium citrate tube; multiply PLTs × 1.11
B. Dilute WBCs 1:10; multiply × 10
C. Perform plasma blank Hgb to correct for lipemia
D. Warm the specimen at 37°C for 15 minutes; rerun the specimen

Answer 11

D. Warm the specimen at 37°C for 15 minutes; rerun the specimen

Question 12

Refer to the following scatterplot, histograms, and automated values for a 33-year-old woman. What follow-up verification procedure is indicated before these results can be released?
A. Perform a manual Hct and redraw the sample using a sodium citrate tube; multiply PLTs× 1.11
B. Dilute WBCs 1:10; multiply × 10
C. Perform plasma blank Hgb to correct for lipemia
D. Warm the specimen at 37°C for 15 minutes; rerun the specimen

Answer 12

C. Perform plasma blank Hgb to correct for lipemia

Question 13

Refer to the following scatterplot, histograms, and automated values for a 48-year-old man. What follow-up verification procedure is indicated before the five-part WBC differential results can be released?
A. Dilute WBCs 1:10; multiply × 10
B. Redraw the sample using a sodium citrate tube; multiply WBCs × 1.11
C. Prepare buffy coat peripheral blood smears, and perform a manual differential
D. Warm specimen at 37°C for 15 minutes; rerun specimen

Answer 13

C. Prepare buffy coat peripheral blood smears, and perform a manual differential

Question 14

Review the following CBC results for a 70-year-old man:
WBC = 58.2 × 109/L MCV = 98 fL
RBC = 2.68 × 1012/L MCH = 31.7 pg
Hgb = 8.5 g/dL MCHC = 32.6%
Hct = 26.5 mL/dL% PLT = 132 × 109/L
Differential: 96 lymphocytes; 2 band neutrophils; 2 segmented neutrophils; 25 smudge cells/100 WBCs
What is the most likely diagnosis on the basis of these values?
A. ALL
B. CLL
C. Infectious mononucleosis
D. Myelodysplastic syndrome

Answer 14

B. CLL

Question 15

Refer to the following scatterplot, histograms, and automated values for a 28-year-old woman who had undergone preoperative laboratory testing. A manual WBC differential was requested by her physician. The WBC differential was not significantly different from the automated five-part differential; however, the medical laboratory scientist noted 3+ elliptocytes/ovalocytes while reviewing the RBC morphology. What is the most likely diagnosis for this patient?
A. DIC
B. HE (ovalocytosis)
C. Cirrhosis
D. Hgb C disease

Answer 15

B. HE (ovalocytosis)

Question 16

A 25-year-old woman presented with symptoms of jaundice, acute cholecystitis, and an enlarged spleen. On investigation, numerous gallstones were discovered. Review the following CBC results:
WBC = 11.1 × 109/L MCV = 100 fL
RBC = 3.33 × 1012/L MCH = 34.5 pg
Hgb = 11.5 g/dL MCHC = 37.5%
Hct = 31.6 mL/dL PLT = 448 × 109/L
WBC differential: 13 band neutrophils; 65 segmented neutrophils; 15 lymphocytes; 6 monocytes; 1 eosinophil RBC morphology: 3+ spherocytes, 1+ polychromasia
What follow-up laboratory test would provide valuable information for this patient?
A. Osmotic fragility test
B. Hgb electrophoresis
C. G6PD assay
D. Methemoglobin reduction test

Answer 16

A. Osmotic fragility test

Question 17

Refer to the following scatterplot, histograms, and automated values for a 53-year-old man who had undergone preoperative laboratory testing. What is the most likely diagnosis for this patient?
A. IDA
B. PV
C. Sideroblastic anemia
D. β-thalassemia minor

Answer 17

D. β-thalassemia minor

Question 18

Review the following CBC results:
WBC = 11.0 × 109/L MCV = 85.0 fL
RBC = 3.52 × 1012/L MCH = 28.4 pg
Hgb = 10.0 g/dL MCHC = 33.4%
Hct = 29.9 mL/dL PLT = 155 × 109/L
12 NRBCs/100 WBCs
RBC morphology: Moderate polychromasia, 3+ target cells, few schistocytes
Which of the following additional laboratory tests would yield informative diagnostic information for this patient?
A. Osmotic fragility test
B. Hgb electrophoresis
C. Sugar water test
D. Bone marrow examination

Answer 18

B. Hgb electrophoresis