CMLA Hematology Basics 5 — Questions and Answers
Question 1: Which test is used to diagnose hereditary spherocytosis?
- Coombs test
- Osmotic fragility test (Correct answer)
- Hemoglobin electrophoresis
- Reticulocyte count
Correct answer: Osmotic fragility test
Hereditary spherocytosis is diagnosed using the osmotic fragility test, which shows increased lysis in hypotonic saline.
Question 2: A CBC shows WBC 2.1 × 10³/μL, RBC 1.8 × 10⁶/μL, and platelets 45 × 10³/μL. This pancytopenia pattern is MOST consistent with:
- Chronic infection
- Aplastic anemia (Correct answer)
- Polycythemia vera
- Chronic myeloid leukemia
Correct answer: Aplastic anemia
Pancytopenia (low WBC, RBC, and platelets) across all cell lines is characteristic of aplastic anemia due to bone marrow failure.
Question 3: In the ABO blood group system, a person with type O blood has:
- A antigens on RBCs and no antibodies
- No antigens on RBCs and both anti-A and anti-B antibodies (Correct answer)
- Both A and B antigens on RBCs
- B antigens on RBCs and anti-A antibodies
Correct answer: No antigens on RBCs and both anti-A and anti-B antibodies
Type O individuals have no A or B antigens on their red cells but carry both anti-A and anti-B antibodies in their plasma.
Question 4: Which morphology is characteristic of iron deficiency anemia on a peripheral smear?
- Macrocytic, normochromic cells
- Microcytic, hypochromic cells (Correct answer)
- Normocytic, normochromic cells
- Macrocytic, hypochromic cells
Correct answer: Microcytic, hypochromic cells
Iron deficiency anemia produces small (microcytic), pale (hypochromic) red blood cells due to inadequate hemoglobin synthesis.
Question 5: The buffy coat layer in a centrifuged blood sample contains:
- Only red blood cells
- Only plasma proteins
- White blood cells and platelets (Correct answer)
- Serum and fibrin
Correct answer: White blood cells and platelets
The buffy coat is the thin white layer between packed RBCs and plasma that contains leukocytes and platelets.
Question 6: Which WBC differential finding is MOST consistent with chronic lymphocytic leukemia (CLL)?
- Marked eosinophilia
- Increased monocytes with large vacuoles
- Marked lymphocytosis with smudge cells (Correct answer)
- Hypersegmented neutrophils
Correct answer: Marked lymphocytosis with smudge cells
CLL classically presents with markedly elevated mature lymphocytes and smudge cells (fragile lymphocytes disrupted during smear preparation).
Question 7: What is the normal reference range for hemoglobin in adult males?
- 10.5–13.5 g/dL
- 12.0–16.0 g/dL
- 13.5–17.5 g/dL (Correct answer)
- 15.0–20.0 g/dL
Correct answer: 13.5–17.5 g/dL
The normal hemoglobin range for adult males is 13.5–17.5 g/dL, which is higher than the female reference range.
CMLA Hematology Basics 5
Which test is used to diagnose hereditary spherocytosis?