CBC Flashcards

*Question: What is the most commonly ordered laboratory test?
A) Urinalysis
B) Complete Blood Count
C) Blood Culture
D) Lipid Panel

*Answer: B) Complete Blood Count

*Question: CBC is usually performed via which method?
A) Manual differential
B) Centrifugation
C) Automated analyzer
D) Flow cytometry

*Answer: C) Automated analyzer

*Question: Which phase of CBC interpretation involves translating numbers into medical terminology?
A) Phase 3
B) Phase 2
C) Phase 1
D) Phase 4

*Answer: C) Phase 1

*Question: Which phase of CBC interpretation involves recognizing disease patterns?
A) Phase 1
B) Phase 4
C) Phase 3
D) Phase 2

*Answer: D) Phase 2

*Question: What is a Delta Check?
A) Comparing results with population averages
B) Comparing current results with the patient's own previous healthy results
C) Comparing male and female reference intervals
D) Comparing automated and manual results

*Answer: B) Comparing current results with the patient's own previous healthy results

*Question: Which of the following is the most reliable indicator of anemia?
A) Hematocrit
B) RBC count
C) Hemoglobin
D) MCV

*Answer: C) Hemoglobin

*Question: According to the Rule of Three, what is the expected hematocrit if hemoglobin is 14 g/dL?
A) 28%
B) 35%
C) 42%
D) 48%

*Answer: C) 42%

*Question: A failing Rule of Three most likely indicates:
A) Microcytic anemia
B) Analytical error
C) Left shift
D) Polycythemia

*Answer: B) Analytical error

*Question: What does an elevated WBC count indicate?
A) Leukopenia
B) Thrombocytosis
C) Leukocytosis
D) Neutropenia

*Answer: C) Leukocytosis

*Question: What does a decreased WBC count indicate?
A) Leukocytosis
B) Leukopenia
C) Lymphocytosis
D) Monocytosis

*Answer: B) Leukopenia

*Question: What is the formula for absolute count?
A) Absolute Count = Relative Count + Total WBC Count
B) Absolute Count = Total WBC Count ÷ Relative Count
C) Absolute Count = Relative Count × Total WBC Count
D) Absolute Count = Relative Count − Total WBC Count

*Answer: C) Absolute Count = Relative Count × Total WBC Count

*Question: A patient has WBC = 13.2 × 10⁹/L and neutrophils at 68%. What is the absolute neutrophil count?
A) 7.2 × 10⁹/L
B) 8.5 × 10⁹/L
C) 9.0 × 10⁹/L
D) 10.2 × 10⁹/L

*Answer: C) 9.0 × 10⁹/L

*Question: Why are absolute counts preferred over relative counts in WBC interpretation?
A) They are easier to calculate
B) Relative counts can be misleading due to proportional changes
C) Absolute counts are reported by all analyzers automatically
D) Relative counts are inaccurate

*Answer: B) Relative counts can be misleading due to proportional changes

*Question: The term "left shift" refers to:
A) Increased mature lymphocytes
B) Decreased neutrophil count
C) Increased immature neutrophilic cells in peripheral blood
D) Shift of platelets to smaller size

*Answer: C) Increased immature neutrophilic cells in peripheral blood

*Question: Who originated the term "left shift"?
A) Wintrobe
B) Arneth
C) Wright
D) Schilling

*Answer: B) Arneth

*Question: What is the Arneth Count based on?
A) RBC morphology
B) Platelet size
C) Neutrophil maturity correlated with segment count
D) Lymphocyte count

*Answer: C) Neutrophil maturity correlated with segment count

*Question: Band cells or cells younger than bands in peripheral blood indicate:
A) Right shift
B) Left shift
C) Leukopenia
D) Lymphocytosis

*Answer: B) Left shift

*Question: Eosinophilic metamyelocytes are counted as:
A) Metamyelocytes
B) Bands
C) Eosinophils with a comment
D) Immature granulocytes

*Answer: C) Eosinophils with a comment

*Question: Which WBC morphologic abnormality is associated with lead poisoning?
A) Hypersegmentation
B) Toxic granulation
C) Döhle bodies
D) Vacuolation

*Answer: B) Toxic granulation

*Question: Hypersegmentation of neutrophils (>5 lobes) is classically seen in:
A) Iron deficiency anemia
B) Thalassemia
C) Megaloblastic anemia
D) Sideroblastic anemia

*Answer: C) Megaloblastic anemia

*Question: NRBCs can falsely affect which CBC parameter?
A) Platelet count
B) Hemoglobin
C) WBC count
D) Hematocrit

*Answer: C) WBC count

*Question: Corrected WBC formula is applied when NRBCs are greater than:
A) 1 per 100 WBCs
B) 3 per 100 WBCs
C) 5 per 100 WBCs
D) 10 per 100 WBCs

*Answer: C) 5 per 100 WBCs

*Question: A patient has 12 NRBCs per 100 WBCs and total WBC of 24 × 10⁹/L. What is the corrected WBC?
A) 19.2 × 10⁹/L
B) 20.0 × 10⁹/L
C) 21.4 × 10⁹/L
D) 22.8 × 10⁹/L

*Answer: C) 21.4 × 10⁹/L

*Question: Which cell type has NO decrease terminology because its reference interval starts near zero?
A) Neutrophil and Lymphocyte
B) Eosinophil and Basophil
C) Monocyte and Neutrophil
D) Lymphocyte and Monocyte

*Answer: B) Eosinophil and Basophil

*Question: What is the MCV reference interval?
A) 60–80 fL
B) 80–100 fL
C) 100–120 fL
D) 70–90 fL

*Answer: B) 80–100 fL

*Question: An MCV below 80 fL is described as:
A) Macrocytic
B) Normocytic
C) Microcytic
D) Hypochromic

*Answer: C) Microcytic

*Question: An MCV above 100 fL is described as:
A) Microcytic
B) Normocytic
C) Hypochromic
D) Macrocytic

*Answer: D) Macrocytic

*Question: Which of the following is NOT included in the TAILS mnemonic for microcytic anemia?
A) Thalassemia
B) Iron Deficiency Anemia
C) Aplastic Anemia
D) Sideroblastic Anemia

*Answer: C) Aplastic Anemia

*Question: What does TAILS stand for in microcytic anemia?
A) Thalassemia, Aplastic anemia, Iron deficiency, Leukemia, Sickle cell
B) Thalassemia, Anemia of Chronic Disease, Iron Deficiency, Lead poisoning, Sideroblastic anemia
C) Thalassemia, Anemia of inflammation, Iron overload, Lymphoma, Spherocytosis
D) Thalassemia, Autoimmune anemia, IDA, Liver disease, Schistocytosis

*Answer: B) Thalassemia, Anemia of Chronic Disease, Iron Deficiency, Lead poisoning, Sideroblastic anemia

*Question: Macrocytic anemia is most commonly associated with deficiency of:
A) Iron and Zinc
B) Folate and Vitamin B12
C) Vitamin C and Iron
D) Calcium and Phosphorus

*Answer: B) Folate and Vitamin B12

*Question: Which parasite causes Vitamin B12 deficiency?
A) Fasciolopsis buski
B) Ascaris lumbricoides
C) Diphyllobothrium latum
D) Taenia solium

*Answer: C) Diphyllobothrium latum

*Question: Which parasite causes Vitamin B12 malabsorption?
A) Diphyllobothrium latum
B) Fasciolopsis buski
C) Enterobius vermicularis
D) Trichuris trichiura

*Answer: B) Fasciolopsis buski

*Question: What is the MCHC formula?
A) MCHC = HGB ÷ RBC × 10
B) MCHC = HCT ÷ RBC × 10
C) MCHC = HGB ÷ HCT × 100
D) MCHC = HCT ÷ HGB × 100

*Answer: C) MCHC = HGB ÷ HCT × 100

*Question: What is the MCH formula?
A) MCH = HGB ÷ HCT × 100
B) MCH = HCT ÷ RBC × 10
C) MCH = HGB ÷ RBC × 10
D) MCH = RBC ÷ HGB × 10

*Answer: C) MCH = HGB ÷ RBC × 10

*Question: What is the MCV formula?
A) MCV = HGB ÷ RBC × 10
B) MCV = HCT ÷ RBC × 10
C) MCV = HGB ÷ HCT × 100
D) MCV = RBC ÷ HCT × 10

*Answer: B) MCV = HCT ÷ RBC × 10

*Question: A normochromic RBC has a central pallor that occupies what fraction of the cell?
A) 1/4
B) 1/2
C) 1/3
D) 2/3

*Answer: C) 1/3

*Question: What does a decreased MCHC indicate?
A) Spherocytosis
B) Hyperchromia
C) Hypochromia
D) Normochromia

*Answer: C) Hypochromia

*Question: What is the maximum MCHC that RBCs can physiologically contain?
A) 30 g/dL
B) 32 g/dL
C) 34 g/dL
D) 36 g/dL

*Answer: D) 36 g/dL

*Question: True hyperchromia in RBCs is:
A) Common in iron deficiency anemia
B) Seen in thalassemia
C) Not physiologically possible
D) Associated with macrocytic anemia

*Answer: C) Not physiologically possible

*Question: An MCHC of approximately 60 g/dL most likely indicates:
A) Spherocytosis
B) Falsely elevated hemoglobin due to lipemia or icterus
C) Iron deficiency anemia
D) Sideroblastic anemia

*Answer: B) Falsely elevated hemoglobin due to lipemia or icterus

*Question: Which conditions can cause falsely elevated MCHC?
A) Dehydration, leukopenia, thrombocytopenia
B) Lipemia, icterus, grossly elevated WBC count
C) Hemolysis, anemia, polycythemia
D) Left shift, right shift, leukocytosis

*Answer: B) Lipemia, icterus, grossly elevated WBC count

*Question: MCHC is best used as what type of parameter?
A) Diagnostic marker
B) Screening tool
C) Internal quality control
D) Confirmatory test

*Answer: C) Internal quality control

*Question: An elevated MCHC (>36 g/dL) with no central pallor and darker cells is most consistent with:
A) Iron deficiency anemia
B) Thalassemia
C) Megaloblastic anemia
D) Spherocytosis

*Answer: D) Spherocytosis

*Question: What does the RDW measure?
A) Average RBC volume
B) Variation in RBC volume (anisocytosis)
C) Hemoglobin content per cell
D) RBC membrane deformability

*Answer: B) Variation in RBC volume (anisocytosis)

*Question: What is the reference interval for RDW?
A) 9.0–11.0%
B) 11.5–14.5%
C) 15.0–18.0%
D) 10.0–13.0%

*Answer: B) 11.5–14.5%

*Question: A narrow RDW histogram indicates:
A) Anisocytosis
B) Macrocytosis
C) Uniform RBC size
D) Microcytosis

*Answer: C) Uniform RBC size

*Question: Which RDW finding has clinical significance?
A) Decreased RDW only
B) Increased RDW only
C) Both increased and decreased
D) Neither; RDW has no clinical significance

*Answer: B) Increased RDW only

*Question: Which combination of CBC parameters provides the most helpful information about RBC size?
A) HGB + HCT
B) MCV + MCHC
C) MCV + RDW
D) RBC count + MCH

*Answer: C) MCV + RDW

*Question: A patient with low MCV and normal RDW most likely has:
A) Iron deficiency anemia
B) Thalassemia trait
C) Megaloblastic anemia
D) Anisocytosis

*Answer: B) Thalassemia trait

*Question: A patient with low MCV and high RDW most likely has:
A) Aplastic anemia
B) Thalassemia trait
C) Iron deficiency anemia
D) Liver disease

*Answer: C) Iron deficiency anemia

*Question: A patient with high MCV and high RDW most likely has:
A) Thalassemia
B) Aplastic anemia
C) Megaloblastic anemia or mixed deficiency
D) Liver disease only

*Answer: C) Megaloblastic anemia or mixed deficiency

*Question: RDW is statistically reported as:
A) Mean and median
B) CV (coefficient of variation) or SD (standard deviation)
C) Percentage and absolute count
D) Ratio and proportion

*Answer: B) CV (coefficient of variation) or SD (standard deviation)

*Question: The reticulocyte count is used to assess:
A) Platelet production
B) WBC maturity
C) Erythropoietic activity of the bone marrow
D) Hemoglobin synthesis

*Answer: C) Erythropoietic activity of the bone marrow

*Question: A patient with anemia and a decreased reticulocyte count suggests:
A) Active hemolysis
B) Iron deficiency
C) Poor bone marrow response; investigate BM failure
D) Vitamin B12 deficiency only

*Answer: C) Poor bone marrow response; investigate BM failure

*Question: The Immature Reticulocyte Fraction (IRF) is:
A) A measure of platelet maturity
B) A sensitive measure of erythropoietic bone marrow activity
C) Used to detect left shift
D) A WBC maturity marker

*Answer: B) A sensitive measure of erythropoietic bone marrow activity

*Question: Is the reticulocyte count a standard component of the CBC?
A) Yes, always included
B) No, it is ordered separately but run on the same analyzer
C) Yes, but only in pediatric patients
D) No, it requires a separate manual method only

*Answer: B) No, it is ordered separately but run on the same analyzer

*Question: When should a Wright-stained peripheral blood film be reviewed?
A) Only when WBC is elevated
B) Whenever platelet count is low
C) Whenever anemia is indicated
D) Only for pediatric patients

*Answer: C) Whenever anemia is indicated

*Question: What is the role of the peripheral blood film in CBC interpretation?
A) It replaces automated analyzer results
B) It serves as quality control — morphology must match analyzer results
C) It is used only when platelet counts are abnormal
D) It provides reticulocyte count

*Answer: B) It serves as quality control — morphology must match analyzer results

*Question: When should RBC morphology be recorded on a report?
A) Always, for every patient
B) Only when cells appear normal
C) Only when abnormalities are present
D) Only for pediatric patients

*Answer: C) Only when abnormalities are present

*Question: Why is RBC count alone unreliable for diagnosing anemia?
A) RBC count is not measurable by analyzers
B) Some anemias like thalassemia have normal or elevated RBC count
C) RBC count fluctuates too rapidly
D) RBC count only measures platelet contamination

*Answer: B) Some anemias like thalassemia have normal or elevated RBC count

*Question: What are the three parameters used for the Rule of Three in assessing anemia?
A) WBC, RBC, Platelets
B) MCV, MCH, MCHC
C) Hematocrit, Hemoglobin, Morphology
D) RDW, MCV, Reticulocyte count

*Answer: C) Hematocrit, Hemoglobin, Morphology

*Question: The MCH is described as following the MCV. What does this mean?
A) MCH and MCV always have the same numerical value
B) Smaller cells hold less hemoglobin; larger cells hold more hemoglobin
C) MCH increases when MCV decreases
D) MCH is calculated from MCV

*Answer: B) Smaller cells hold less hemoglobin; larger cells hold more hemoglobin

*Question: Which RBC index is considered the LEAST clinically useful when other parameters are available?
A) MCV
B) MCHC
C) MCH
D) RDW

*Answer: C) MCH

*Question: An increased platelet count is termed:
A) Thrombocytopenia
B) Thrombocytosis
C) Pancytopenia
D) Pancytosis

*Answer: B) Thrombocytosis

*Question: A decreased platelet count is termed:
A) Thrombocytosis
B) Pancytosis
C) Thrombocytopenia
D) Leukopenia

*Answer: C) Thrombocytopenia

*Question: What is the reference interval for MPV?
A) 4.5–6.5 fL
B) 6.9–10.2 fL
C) 10.5–13.0 fL
D) 7.5–12.5 fL

*Answer: B) 6.9–10.2 fL

*Question: MPV is the platelet counterpart of which RBC parameter?
A) HGB
B) RDW
C) MCHC
D) MCV

*Answer: D) MCV

*Question: Platelet satellitosis refers to:
A) Platelet clumping in the tube
B) Platelets attached to WBCs
C) Giant platelets seen on PBS
D) Agranular platelets

*Answer: B) Platelets attached to WBCs

*Question: Why is platelet satellitosis clinically important?
A) It indicates thrombocytosis
B) It can falsely affect platelet count accuracy
C) It is a sign of megaloblastic anemia
D) It causes spurious leukocytosis

*Answer: B) It can falsely affect platelet count accuracy

*Question: Reduced platelet granules are described as:
A) Agranular
B) Dysplastic
C) Hypogranular
D) Bizarre

*Answer: C) Hypogranular

*Question: Absent platelet granules are described as:
A) Hypogranular
B) Agranular
C) Dysplastic
D) Giant

*Answer: B) Agranular

*Question: Pancytopenia is most suggestive of which conditions?
A) Polycythemia vera and CML
B) Acute leukemia and aplastic anemia
C) Iron deficiency anemia and thalassemia
D) Infection and inflammation

*Answer: B) Acute leukemia and aplastic anemia

*Question: Pancytosis is most associated with which condition?
A) Aplastic anemia
B) Acute leukemia
C) Polycythemia vera
D) Megaloblastic anemia

*Answer: C) Polycythemia vera

*Question: Which strategy helps determine significance when two diagnostically related parameters are slightly outside the reference interval in the same direction?
A) Delta check
B) Manual differential
C) Two-parameter rule — both outside interval in same direction suggests clinical significance
D) Reticulocyte count

*Answer: C) Two-parameter rule — both outside interval in same direction suggests clinical significance

*Question: Which cell classification system for RBC size was introduced by Wintrobe?
A) Arneth classification
B) Morphologic classification using MCV
C) Wright classification
D) Schilling index

*Answer: B) Morphologic classification using MCV

*Question: If a patient is normocytic, what additional test should be checked to determine if there is an underlying abnormality?
A) MCHC
B) MCH
C) Reticulocyte count
D) MPV

*Answer: C) Reticulocyte count

*Question: Hematocrit can be falsely elevated due to:
A) Lipemia
B) Dehydration
C) Icterus
D) Leukocytosis

*Answer: B) Dehydration

*Question: Which of the following is a characteristic feature of spherocytes on peripheral blood smear?
A) Large central pallor and pale color
B) No central pallor, darker appearance
C) Elongated shape with pointed ends
D) Target cell appearance

*Answer: B) No central pallor, darker appearance

*Question: A patient with normal MCV, normal MCHC, but elevated RDW with size variation on PBS is most likely experiencing:
A) Thalassemia trait
B) Iron deficiency anemia
C) Anisocytosis with normocytic normochromic RBCs
D) Spherocytosis

*Answer: C) Anisocytosis with normocytic normochromic RBCs

*Question: Which CBC finding in a patient with anemia suggests inadequate bone marrow response?
A) Elevated reticulocyte count
B) Decreased reticulocyte count
C) Elevated RDW
D) Decreased MCV

*Answer: B) Decreased reticulocyte count

*Question: What WBC parameter should be evaluated first to ensure accurate CBC interpretation?
A) Relative differential
B) Absolute differential
C) Accurate total WBC count
D) WBC morphology

*Answer: C) Accurate total WBC count

*Question: A CBC showing decreased WBC, decreased RBC/HGB, and decreased platelets is consistent with:
A) Polycythemia vera
B) Infection
C) Pancytopenia — suggesting aplastic anemia or acute leukemia
D) Thalassemia

*Answer: C) Pancytopenia — suggesting aplastic anemia or acute leukemia

*Question: Which of the following interferes with the spectrophotometric measurement of hemoglobin and causes falsely elevated MCHC?
A) Dehydration and hypernatremia
B) Lipemia, icterus, and grossly elevated WBC counts
C) Anemia and thrombocytopenia
D) Left shift and leukocytosis

*Answer: B) Lipemia, icterus, and grossly elevated WBC counts