Hematology Problem Solving Flashcards
- 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
B. 16.7 × 109/L
- 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
C. 20.0 × 109/L
- A manual RBC count is performed on a 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
D. 250.0 × 109/L
- Review the scatterplot of white blood cells shown.
Which section of the scatterplot denotes the
number of monocytes?
A. A
B. B
C. C
D. D
A. A
- Review the following automated CBC values.
WBCs = 17.5 × 109/L (flagged) MCV = 86.8 fL
RBCs = 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 upon review of the
peripheral blood smear.
Based on 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
C. WBC/perform manual WBC count
- Review the following CBC results on a 2-day-old
infant:
WBCs = 15.2 × 109/L
MCV = 105 fL
RBCs = 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
D. Normal values for a 2-day-old infant
- Review the following scatterplot, histograms, and
automated values on 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. Chronic lymphocytic leukemia
D. β-Thalassemia
A. Infectious mononucleosis
- Lymphocytosis with numerous atypical lymphocytes
is a hallmark finding consistent with the diagnosis
of infectious mononucleosis. The automated results
demonstrated abnormal WBC subpopulations,
specifically lymphocytosis as well as monocytosis.
However, on peripheral smear examination,
60 atypical lymphocytes and only 6 monocytes
were noted. Atypical lymphocytes are often
misclassified by automated cell counters as
monocytes. Therefore, the automated analyzer
differential must not be released and the manual
differential count must be relied upon for diagnostic
interpretation.
- Review the following scatterplot, histograms, and
automated values on 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. Chronic myelocytic leukemia
C. Acute myelocytic leukemia
D. Megaloblastic leukemia
B. Chronic myelocytic leukemia
- The +++++ on the printout indicates that the WBC
count exceeds the upper linearity of the analyzer
(>99.9 × 109/L). This markedly elevated WBC count,
combined with the spectrum of immature
granulocytic cells seen on peripheral smear
examination, indicates the diagnosis of chronic
myelocytic leukemia.
- Review the automated results from the previous
question (Chronic myelocytic leukemia).
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
D. None of the automated counts can be released
without follow-up verification
- All of the automated results have R or review flags
indicated; none can be released without verification
procedures. The specimen must be diluted to bring
the WBC count within the linearity range of the
analyzer. When enumerating the RBC count, the
analyzer does not lyse the WBCs and actually counts
them in with the RBC count. As such, the RBC count is
falsely elevated because of the increased number of
WBCs. Therefore, after an accurate WBC count has
been obtained, this value can be subtracted from the
RBC count to obtain a true RBC count. For example,
using the values for this patient:
Step 1: Obtain an accurate WBC count by diluting the
sample 1:10.
WBC = 41.0 × 10 (dilution) = 410 × 109/L
Step 2: Convert this value to cells per 1012 in order to
subtract from the RBC count.
410 × 109/L = 0.41 × 1012/L
Step 3: Subtract the WBC count from the RBC count
to get an accurate RBC count.
3.28 (original RBC) – 0.41 (true WBC) =
2.87 × 1012/L = accurate RBC
The Hct may be obtained by microhematocrit
centrifugation. The true MCV may be obtained using
the standard formula.
MCV = (Hct ÷ RBC) × 10
where RBC = RBC count in millions per microliter
Additionally, the platelet count must be verified by
smear estimate or performed manually.
- Refer to the following scatterplot, histograms, and
automated values on a 45-year-old man. What
follow-up verification procedure is indicated
before releasing these results?
A. Redraw blood sample using a sodium citrate
tube; multiply PLTs × 1.11
B. Dilute the 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
A. Redraw blood sample using a sodium citrate
tube; multiply PLTs × 1.11
- Refer to the following scatterplot, histograms, and
automated values on a 52-year-old woman. What
follow-up verification procedure is indicated
before releasing these results?
A. Redraw specimen using a sodium citrate tube;
multiply PLT × 1.11
B. Dilute the 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
D. Warm the specimen at 37°C for 15 minutes;
rerun the specimen
- The presence of a high titer cold agglutinin in a
patient with cold autoimmune hemolytic anemia
will interfere with automated cell counting. The
most remarkable findings are a falsely elevated MCV,
MCH, and MCHC as well as a falsely decreased RBC
count. The patient’s red blood cells will quickly
agglutinate in vitro when exposed to ambient
temperatures below body temperature. To correct
this phenomenon, incubate the EDTA tube at 37°C
for 15–30 minutes and then rerun the specimen
- Refer to the following scatterplot, histograms, and
automated values on a 33-year-old woman. What
follow-up verification procedure is indicated
before releasing these results?
A. Perform a manual hematocrit and redraw the
sample using a sodium citrate tube; multiply
PLT × 1.11
B. Dilute the WBC 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
C. Perform plasma blank Hgb to correct for lipemia
- The rule of thumb regarding the Hgb/Hct correlation
dictates that Hgb × 3 ≈ Hct (± 3). This rule is violated
in this patient; therefore, a follow-up verification
procedure is indicated. Additionally, the MCHC is
markedly elevated in these results, and an
explanation for a falsely increased Hgb should be
investigated. Lipemia can be visualized by
centrifuging the EDTA tube and observing for a milky
white plasma. To correct for the presence of lipemia,
a plasma Hgb value (baseline Hgb) should be
ascertained using the patient’s plasma and
subsequently subtracted from the original falsely
elevated Hgb value. The following formula can be
used to correct for lipemia.
Whole blood Hgb – [(Plasma Hgb)
(1– Hct/100)] = Corrected Hgb
- Refer to the following scatterplot, histograms, and
automated values on a 48-year-old man. What
follow-up verification procedure is indicated before
releasing the five-part WBC differential results?
A. Dilute WBCs 1:10; multiply × 10
B. Redraw the sample using a sodium citrate tube;
multiply WBC × 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
C. Prepare buffy coat peripheral blood smears and
perform a manual differential
- The markedly decreased WBC count (0.2 × 109/L)
indicates that a manual differential is necessary and
very few leukocytes will be available for differential
cell counting. To increase the yield and thereby
facilitate counting, differential smears should be
prepared using the buffy coat technique.
Review the following CBC results on a 70-year-old
man:
WBCs = 58.2 × 109/L
MCV = 98 fL
RBCs = 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 based on these
values?
A. Acute lymphocytic leukemia
B. Chronic lymphocytic leukemia (CLL)
C. Infectious mononucleosis
D. Myelodysplastic syndrome
B. Chronic lymphocytic leukemia (CLL)
- CLL is a disease of the elderly, classically associated
with an elevated WBC count and relative and
absolute lymphocytosis. CLL is twice as common in
men, and smudge cells (WBCs with little or no
surrounding cytoplasm) are usually present in the
peripheral blood smear. CLL may occur with or
without anemia or thrombocytopenia. The patient’s
age and lack of blasts rule out acute lymphocytic
leukemia. Similarly, the patient’s age and the lack of
atypical lymphocytes make infectious mononucleosis
unlikely. Myelodysplastic syndromes may involve the
erythroid, granulocytic, or megakaryocytic cell lines
but not the lymphoid cells.
- Refer to the following scatterplot, histograms, and
automated values on a 28-year-old woman who had
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 technologist noted 3+ elliptocytes/ovalocytes
while reviewing the RBC morphology. What is the
most likely diagnosis for this patient?
A. Disseminated intravascular coagulation (DIC)
B. Hereditary elliptocytosis (ovalocytosis)
C. Cirrhosis
D. Hgb C disease
B. Hereditary elliptocytosis (ovalocytosis)
- The finding of ovalocytes as the predominant RBC
morphology in peripheral blood is consistent with
the diagnosis of hereditary elliptocytosis (HE), or
ovalocytosis. This disorder is relatively common and
can range in severity from an asymptomatic carrier to
homozygous HE with severe hemolysis. The most
common clinical subtype is associated with no or
minimal hemolysis. Therefore, HE is usually associated
with a normal RBC histogram and cell indices and will
go unnoticed without microscopic evaluation of the
peripheral smear.
- Refer to the following scatterplot, histograms, and
automated values on a 53-year-old man who had
preoperative laboratory testing. What is the most
likely diagnosis for this patient?
A. Iron deficiency anemia (IDA)
B. Polycythemia vera (PV)
C. Sideroblastic anemia
D. β-Thalassemia minor
D. β-Thalassemia minor
