Practice Questions

What type of anemia is typically associated with an MCV < 80 fL?

a) Macrocytic anemia

b) Normocytic anemia

c) Microcytic anemia

d) Megaloblastic anemia

c) Microcytic anemia

T/F Vitamin B12 deficiency causes a macrocytic anemia and may lead to neurological symptoms.

True

Which of the following lab results is most characteristic of iron deficiency anemia?

a) High ferritin, high serum iron

b) Low ferritin, high TIBC

c) High ferritin, low TIBC

d) Normal ferritin, low TIBC

b) Low ferritin, high TIBC

Name two characteristic RBC morphologies seen in iron deficiency anemia.

Target Cells

Tear drop Cells

Iron Deficiency anemia is Micro/Macro/Normocytic and Normo/Hyper/Hypochromic

Microcytic and Hypochromic

Which lab findings are common in hemolytic anemias? (Select all that apply)

a) ↑ Reticulocyte count

b) ↓ LDH

c) ↑ Unconjugated bilirubin

d) ↓ Haptoglobin

A, C, D

What lab marker differentiate B12 deficiency from folate deficiency?

MMA

Deletion of how many alpha genes results in HbH disease?

a) 1

b) 2

c) 3

d) 4

C) 3

What hemoglobin is present in a fetus with 4-gene alpha deletion (Hydrops fetalis)?

Hb Barts

In beta-thalassemia major, which hemoglobins are elevated and which are absent?

Elevated: HbF, HbA2

Absent: HbA

What RBC morphologies are commonly seen in thalassemias?

Target cells, basophilic stippling, NRBCs

Thalassemia is Micro/Macro/Normocytic and Normo/Hyper/Hypochromic

Microcytic and Hypochromic

Auer rods are seen in:

a) ALL

b) AML

c) CLL

d) CML

B) AML

Which leukemia is most common in children?

ALL

Which genetic abnormality is associated with CML?

a) t(15;17)

b) t(8;14)

c) t(9;22)

d) t(14;18)

c) t(9;22)

Philadelphia chromosome is associated with which Leukemia?

CML

T/F CLL often presents with high WBCs and smudge cells on peripheral smear.

True

What stain is positive in hairy cell leukemia?

TRAP

Which cell is typically seen in hereditary spherocytosis or autoimmune hemolytic anemia?

Spherocytes

Which RBC abnormality is associated with lead poisoning and thalassemia?

Basophilic stippling

Hypersegmented neutrophils are associated with what deficiencies?

Vitamin B12 and folate deficiency

Which anemia has normal RDW, target cells, and increased HbA2 on electrophoresis?

Beta Thalassemia

Which anemia shows ringed sideroblasts in the bone marrow?

Sideroblastic anemia

Which lab values are opposite in iron deficiency anemia vs anemia of chronic disease?

Iron: decrease ferritin and increase TIBC

Chronic: Increase ferritin and decrease TIBC

What type of anemia is associated with basophilic stippling and lead poisoning?

Sideroblastic anemia or lead poisoning

 Which anemias are associated with elevated reticulocyte count?

Hemolytic anemias (e.g., G6PD, hereditary spherocytosis, AIHA)

A catalase-positive, gram-positive cocci in clusters is isolated from a wound. Which test would you perform next to differentiate Staphylococcus aureus from other Staphylococci?

A. Coagulase test

B. Oxidase test

C. CAMP test

D. Bile esculin test

A. Coagulase test

A child presents with cola-colored urine. Urinalysis reveals RBC casts, proteinuria, and mild hematuria. Which condition is most likely?

A. Cystitis

B. Nephrotic syndrome

C. Acute glomerulonephritis

D. Diabetes insipidus

C. Acute glomerulonephritis

Which of the following is most characteristic of nephrotic syndrome on urinalysis?

A. Large amounts of WBCs and bacteria

B. RBC casts and moderate protein

C. Fatty casts and >3.5 g/day proteinuria

D. Hemoglobinuria and low pH

C. Fatty casts and >3.5 g/day proteinuria

A urine specimen is turbid and smells foul. Microscopy shows bacteria, WBCs, and squamous epithelial cells. What is the likely pre-analytical error?

A. Contamination from vaginal flora

B. Improper reagent strip calibration

C. Hemolysis in collection tube

D. Excessive refrigeration

A. Contamination from vaginal flora

What crystal is commonly seen in acidic urine and resembles envelopes under the microscope?

A. Uric acid

B. Calcium oxalate

C. Triple phosphate

D. Cystine

B. Calcium oxalate

A positive Clinitest but negative glucose on dipstick suggests:

A. False positive dipstick

B. Presence of galactose

C. Bacterial contamination

D. Diabetic ketoacidosis

B. Presence of galactose

Which of the following casts is most associated with acute tubular necrosis (ATN)?

A. RBC casts

B. Broad waxy casts

C. Granular (muddy brown) casts

D. Fatty casts

C. Granular (muddy brown) casts

A patient presents with fatigue, joint pain, and a positive ANA test showing a homogeneous (diffuse) pattern. Which disease is most likely?

A. Systemic lupus erythematosus (SLE)

B. Sjögren’s syndrome

C. Scleroderma

D. CREST syndrome

A. Systemic lupus erythematosus (SLE)

An ANA test reveals a speckled pattern. This pattern is the most nonspecific and may be seen in all of the following EXCEPT:

A. SLE

B. Mixed connective tissue disease (MCTD)

C. Sjögren’s syndrome

D. Goodpasture’s syndrome

D. Goodpasture’s syndrome

Which ANA pattern is most commonly associated with anti-centromere antibodies and CREST syndrome (a limited form of scleroderma)?

A. Homogeneous

B. Nucleolar

C. Speckled

D. Centromere

D. Centromere

Which chromosomal translocation is associated with chronic myelogenous leukemia (CML)?

A. t(15;17)

B. t(9;22)

C. t(8;21)

D. t(12;21)

B. t(9;22)

Auer rods are most commonly found in which leukemia?

A. ALL

B. AML

C. CLL

D. Hairy cell leukemia

B. AML

Sudan Black B stain is most helpful in identifying:

A. Lymphoblasts

B. Plasma cells

C. Myeloblasts

D. Monoblasts

C. Myeloblasts

A 5-year-old child presents with fatigue, bone pain, and bruising. CBC shows pancytopenia with 80% lymphoblasts. The most likely diagnosis is:

A. AML

B. ALL

C. CML

D. CLL

B. ALL

Which of the following findings is most consistent with chronic myelogenous leukemia (CML) on peripheral smear?

A. Pancytopenia and blasts

B. Marked lymphocytosis with smudge cells

C. Left shift with all stages of granulocyte maturation and basophilia

D. Increased monocytes with folded nuclei

C. Left shift with all stages of granulocyte maturation and basophilia

A blood smear shows numerous small, mature-appearing lymphocytes and smudge cells. This is most consistent with:

A. CML

B. ALL

C. AML

D. CLL

D. CLL

HIV primarily infects which type of immune cells?

   A. B lymphocytes

   B. Cytotoxic T cells

   C. Helper T cells

   D. Neutrophils

C. Helper T cells

The “window period” in HIV infection refers to:

   A. When symptoms first appear

   B. When antibodies are undetectable but the person is infectious

   C. When HIV is cleared from the blood

   D. The incubation period for AIDS

B. When antibodies are undetectable but the person is infectious

Which of the following is the most specific confirmatory test for HIV?

   A. ELISA

   B. Rapid antigen test

   C. Western blot (or immunoblot)

   D. Viral culture

C. Western blot (or immunoblot)

Which of the following is included in the CDC-recommended HIV 4th generation test?

A. Only anti-HIV antibodies

B. Only HIV p24 antigen

C. HIV antibodies and p24 antigen

D. HIV DNA

C. HIV antibodies and p24 antigen

Serum sickness is an example of which type of hypersensitivity?

A. Type I

B. Type II

C. Type III

D. Type IV

C. Type III

What type of hypersensitivity is involved in autoimmune hemolytic anemia?

A. Type I

B. Type II

C. Type III

D. Type IV

B. Type II

Which hypersensitivity reaction is responsible for anaphylaxis?

A. Type I

B. Type II

C. Type III

D. Type IV

A. Type I

The decrease in which cell count is used to monitor HIV progression to AIDS?

A. CD3

B. CD8

C. CD4

D. CD19

C. CD4

A patient presents with dry eyes, dry mouth, and a speckled ANA pattern. Which antibodies are most commonly associated with this condition?

A. Anti-dsDNA and anti-Sm

B. Anti-SSA (Ro) and anti-SSB (La)

C. Anti-histone and anti-RNP

D. Anti-centromere and anti-Scl-70

B. Anti-SSA (Ro) and anti-SSB (La)

Which of the following immunophenotypes is most consistent with precursor B-cell ALL?

A. CD13+, CD33+

B. CD19+, CD10+

C. CD3+, CD7+

D. CD14+, CD64+

B. CD19+, CD10+

The leukemia most commonly associated with the translocation t(15;17) is:

A. CML

B. Acute promyelocytic leukemia (APL)

C. ALL

D. Hairy cell leukemia

B. Acute promyelocytic leukemia (APL)

The presence of tartrate-resistant acid phosphatase (TRAP)-positive cells is diagnostic for:

A. CLL

B. AML

C. Hairy cell leukemia

D. ALL

C. Hairy cell leukemia

A peripheral blood smear shows many large, immature cells with fine chromatin, prominent nucleoli, and scant cytoplasm. Myeloperoxidase stain is strongly positive. What type of leukemia is most likely?

A. Acute lymphoblastic leukemia (ALL)

B. Acute myeloid leukemia (AML)

C. Chronic myelogenous leukemia (CML)

D. Chronic lymphocytic leukemia (CLL)

B. Acute myeloid leukemia (AML)

A patient has an ANA test with a rim (peripheral) pattern. Which autoantibody and disease are most associated with this pattern?

A. Anti-SSA; Sjögren’s

B. Anti-dsDNA; SLE

C. Anti-Sm; MCTD

D. Anti-RNP; Raynaud’s

B. Anti-dsDNA; SLE

What cytochemical stain is useful for identifying monocytic leukemia (AML M5)?

A. Myeloperoxidase (MPO)

B. Sudan Black B

C. Nonspecific esterase (NSE)

D. Acid phosphatase

C. Nonspecific esterase (NSE)

A CBC shows WBC 150,000/µL with marked left shift, basophilia, and no significant increase in blasts. The LAP (leukocyte alkaline phosphatase) score is very low. What is the likely diagnosis?

A. Leukemoid reaction

B. Chronic lymphocytic leukemia

C. Chronic myelogenous leukemia

D. Acute leukemia

C. Chronic myelogenous leukemia

What is the target substrate used in standard ANA indirect immunofluorescence testing?

A. Mouse liver

B. Human epithelial cells

C. HEp-2 cells

D. Rat kidney cells

C. HEp-2 cells

A patient has a positive ANA with a coarse speckled nuclear pattern and symptoms suggestive of Raynaud’s, myositis, and arthritis. What is the likely autoantibody?

A. Anti-dsDNA

B. Anti-RNP

C. Anti-histone

D. Anti-SSA

B. Anti-RNP

A nucleolar ANA pattern is observed on indirect immunofluorescence. Which condition is most strongly associated with this pattern?

A. Rheumatoid arthritis

B. Drug-induced lupus

C. Diffuse systemic sclerosis (scleroderma)

D. Hashimoto’s thyroiditis

C. Diffuse systemic sclerosis (scleroderma)

A urine sample is dark brown and tests positive for blood on dipstick, but no RBCs are seen under the microscope. What is the most likely explanation?

A. Hematuria

B. Hemoglobinuria

C. Myoglobinuria

D. Biliary obstruction

C. Myoglobinuria

A young female has positive ANA testing, proteinuria, and hematuria. Her ANA shows a homogeneous and peripheral** pattern. Which confirmatory test is most appropriate?

A. Anti-RNP ELISA

B. Anti-histone antibodies

C. Anti-dsDNA by ELISA or Crithidia

D. RF and CCP antibodies

C. Anti-dsDNA by ELISA or Crithidia

Urine dipstick shows:

• pH: 8.5

• Protein: trace

• Nitrite: positive

• Leukocyte esterase: positive

What does the alkaline pH suggest about the likely organism?

A. Streptococcus

B. Escherichia coli

C. Proteus mirabilis

D. Staphylococcus saprophyticus

C. Proteus mirabilis

Urinalysis shows the following:

• Positive leukocyte esterase

• Positive nitrites

• Many WBCs on microscopic exam

What is the most likely diagnosis?

A. Acute glomerulonephritis

B. Cystitis (UTI)

C. Nephrotic syndrome

D. Pyelonephritis

B. Cystitis (UTI)

A patient’s urine has a fruity odor and tests strongly positive for ketones. What is the most likely underlying condition?

A. Urinary tract infection

B. Diabetes mellitus

C. Liver disease

D. Dehydration

B. Diabetes mellitus

Patient:72-year-old male with confusion, weakness, and recent diuretic use

Labs:

• Na⁺: 125 mmol/L

• K⁺: 3.2 mmol/L

• Cl⁻: 95 mmol/L

• HCO₃⁻: 24 mmol/L

• BUN: 18 mg/dL

• Creatinine: 1.1 mg/dL

What is the most likely cause of this patient’s symptoms?

a) Hypernatremia

b) SIADH

c) Hyponatremia due to diuretic use

d) Hyperkalemia

c) Hyponatremia due to diuretic use

Sodium range

136 – 145 mmol/L

Potassium range

3.5 – 5.1 mmol/L

Chloride range

98 – 107 mmol/L

Patient: 24-year-old female with type 1 diabetes, vomiting, and deep rapid breathing

Labs:

• Glucose: 620 mg/dL

• Na⁺: 130 mmol/L

• K⁺: 5.8 mmol/L

• HCO₃⁻: 12 mmol/L

• Anion Gap: ↑

• pH: 7.25

• Urine: Positive for ketones and glucose

What is the most likely diagnosis?

a) Hyperosmolar hyperglycemic state (HHS)

b) Metabolic alkalosis

c) Diabetic ketoacidosis (DKA)

d) Lactic acidosis

c) Diabetic ketoacidosis (DKA)

Patient: 68-year-old male with fatigue, bone pain, and recurrent infections

• Total protein: ↑

• Albumin: ↓

• SPEP: Sharp monoclonal spike in gamma region

• Urine: Bence Jones protein +

What is the most likely diagnosis?

a) Waldenstrom macroglobulinemia

b) Multiple myeloma

c) Chronic infection

d) Liver cirrhosis

b) Multiple myeloma

ABG Results:

• pH: 7.32

• pCO₂: 60 mmHg

• HCO₃⁻: 30 mmol/L

What is the primary acid-base disorder?

a) Respiratory alkalosis

b) Metabolic acidosis

c) Respiratory acidosis with compensation

d) Mixed acid-base disorder

c) Respiratory acidosis with compensation

Patient: 55-year-old female with abdominal bloating and weight loss

Labs:

• CA-125: Significantly elevated

• CEA: Normal

• AFP: Normal

Which malignancy is most likely?

a) Colon cancer

b) Hepatocellular carcinoma

c) Ovarian cancer

d) Pancreatic cancer

c) Ovarian cancer

Patient: 50-year-old male with fatigue, jaundice, and alcohol use

Labs:

• AST: 240 U/L

• ALT: 90 U/L

• ALP: 160 U/L

• Total bilirubin: 4.2 mg/dL

• Direct bilirubin: 1.3 mg/dL

• Albumin: 2.8 g/dL

• PT: Prolonged

Which of the following is most consistent with these findings?

a) Acute hepatitis A infection

b) Alcoholic hepatitis

c) Obstructive jaundice

d) Gilbert syndrome

b) Alcoholic hepatitis

Patient: 40-year-old male with severe epigastric pain radiating to the back

Labs:

• Amylase: 430 U/L

• Lipase: 760 U/L

• Triglycerides: 820 mg/dL

• ALT, AST: Mildly elevated

What is the most likely diagnosis?

a) Acute cholecystitis

b) Peptic ulcer disease

c) Acute pancreatitis

d) Pancreatic cancer

c) Acute pancreatitis

Patient: 67-year-old male with hypertension and fatigue

Labs:

• BUN: 48 mg/dL

• Creatinine: 3.2 mg/dL

• eGFR: ↓

• Potassium: 5.6 mmol/L

• Urinalysis: Proteinuria, granular casts

What condition is most consistent with these findings?

a) Acute glomerulonephritis

b) Chronic kidney disease

c) Prerenal azotemia

d) Nephrotic syndrome

b) Chronic kidney disease

Patient: 45-year-old woman with weight loss, heat intolerance, and anxiety

Labs:

• TSH: <0.01 µIU/mL

• Free T4: ↑

• Total T3: ↑

• TSI (Thyroid-stimulating immunoglobulin): Positive

What is the most likely diagnosis?

a) Hashimoto thyroiditis

b) Grave's disease

c) Subclinical hypothyroidism

d) Non-thyroidal illness

b) Grave's disease

Patient: 58-year-old male with chest pain radiating to the arm

Labs:

• CK-MB: ↑

• Troponin I: 6.2 ng/mL (normal <0.04)

• Myoglobin: ↑

• ECG: ST elevation

What do these results most likely indicate?

a) Stable angina

b) Myocardial infarction

c) Congestive heart failure

d) Pulmonary embolism

b) Myocardial infarction

Which of the following characteristics best differentiates Staphylococcus epidermidis from Staphylococcus saprophyticus?

A. Catalase reaction

B. Mannitol fermentation

C. Novobiocin susceptibility

D. Coagulase production

C. Novobiocin susceptibility

Which test differentiates Enterobacter spp. from Escherichia coli?

A. Indole

B. Citrate

C. Lactose fermentation

D. Catalase

B. Citrate

A gram-positive cocci in clusters is catalase-positive and coagulase-negative. It is resistant to novobiocin. What is the most likely organism?

A. Staphylococcus aureus

B. Staphylococcus saprophyticus

C. Staphylococcus epidermidis

D. Micrococcus luteus

B. Staphylococcus saprophyticus

What set of biochemical results would most likely identify Klebsiella pneumoniae?

A. Indole-positive, citrate-negative, urease-negative

B. Indole-negative, citrate-positive, urease-positive

C. Indole-positive, citrate-positive, urease-negative

D. Indole-negative, citrate-negative, urease-positive

B. Indole-negative, citrate-positive, urease-positive

Which of the following Enterobacteriaceae is non-lactose fermenting on MacConkey agar, H2S-positive, and negative for urease?

A. Shigella spp.

B. Proteus vulgaris

C. Salmonella spp.

D. Klebsiella spp.

C. Salmonella spp.

A gram-negative rod is H2S-positive, urease-positive, and phenylalanine deaminase (PAD) positive. What is the most likely organism?

A. Escherichia coli

B. Proteus mirabilis

C. Salmonella enterica

D. Klebsiella pneumoniae

B. Proteus mirabilis

A lactose-fermenting gram-negative rod shows positive indole and methyl red reactions, but negative for citrate and VP. What is the most likely organism?

A. Klebsiella pneumoniae

B. Escherichia coli

C. Enterobacter cloacae

D. Proteus mirabilis

B. Escherichia coli

What biochemical test distinguishes Proteus spp. from most other Enterobacteriaceae?

A. Indole

B. Phenylalanine deaminase (PAD)

C. Urease

D. Oxidase

B. Phenylalanine deaminase (PAD)

Which organism shows the following results: Lactose-fermenter, indole-negative, citrate-positive, VP-positive, urease-positive?

A. Escherichia coli

B. Enterobacter cloacae

C. Klebsiella pneumoniae

D. Proteus vulgaris

C. Klebsiella pneumoniae

Which hypersensitivity type is delayed and T-cell mediated?

A. Type I

B. Type II

C. Type III

D. Type IV

D. Type IV

Which CD marker is typically used to identify cytotoxic T cells?

A. CD4

B. CD8

C. CD20

D. CD56

B. CD8

Natural killer (NK) cells are typically identified by which markers?

A. CD3⁺ CD4⁺

B. CD19⁺ CD20⁺

C. CD16⁺ CD56⁺

D. CD8⁺ CD4⁻

C. CD16⁺ CD56⁺

Which surface marker is most associated with B lymphocytes?

A. CD4

B. CD8

C. CD3

D. CD19

D. CD19

Which cluster of differentiation (CD) marker is found on all mature T-cells?

A. CD20

B. CD3

C. CD10

D. CD16

B. CD3

Which surface marker is found on all T-helper cells?

A. CD4

B. CD8

C. CD3

D. CD19

A. CD4

Which antibody is most responsible for Type I hypersensitivity reactions?

A. IgG

B. IgA

C. IgE

D. IgM

C. IgE

Which Weiner notation represents the rare Fisher-Race genotype “DCE”?

A. Rᶻ

B. R₁

C. Rᵧ

D. rᶻ

A. Rᶻ

What is the normal reference range for arterial pH?

A. 7.20–7.30

B. 7.35–7.45

C. 7.45–7.55

D. 6.8–7.0

B. 7.35–7.45

A pH of 7.25, pCO₂ of 55 mmHg, and HCO₃⁻ of 24 mmol/L suggests:

A. Metabolic acidosis

B. Respiratory acidosis

C. Metabolic alkalosis

D. Respiratory alkalosis

B. Respiratory acidosis

Which compensatory mechanism is expected in metabolic acidosis?

A. Hypoventilation

B. Hyperventilation

C. Renal retention of H⁺

D. Increased HCO₃⁻ secretion

B. Hyperventilation

4. What is the primary buffer system in blood?

A. Phosphate buffer

B. Hemoglobin buffer

C. Bicarbonate buffer

D. Protein buffer

C. Bicarbonate buffer