CMLA Hematology Basics 4 — Questions and Answers
Question 1: A reticulocyte count of 8% in a patient with hemolytic anemia indicates:
- Bone marrow failure
- Appropriate bone marrow response (Correct answer)
- Aplastic anemia
- Iron deficiency
Correct answer: Appropriate bone marrow response
An elevated reticulocyte count in hemolytic anemia indicates the bone marrow is compensating by increasing red cell production.
Question 2: Which stain is used to identify reticulocytes in a blood smear?
- Wright stain
- Gram stain
- New methylene blue (Correct answer)
- Giemsa stain
Correct answer: New methylene blue
New methylene blue (supravital stain) precipitates residual RNA in reticulocytes, making them visible as blue-stained cells.
Question 3: What does MCV measure?
- Average hemoglobin per red cell
- Average volume of a single red blood cell (Correct answer)
- Total number of red cells per liter
- Percentage of blood occupied by red cells
Correct answer: Average volume of a single red blood cell
MCV (Mean Corpuscular Volume) measures the average size (volume) of individual red blood cells in femtoliters.
Question 4: Schistocytes (red cell fragments) on a peripheral smear are MOST suggestive of:
- Iron deficiency anemia
- Microangiopathic hemolytic anemia (Correct answer)
- B12 deficiency
- Polycythemia vera
Correct answer: Microangiopathic hemolytic anemia
Schistocytes result from mechanical fragmentation of RBCs in conditions like TTP, HUS, and DIC (microangiopathic hemolytic anemias).
Question 5: Which platelet count threshold typically requires transfusion to prevent spontaneous bleeding?
- Below 150,000/μL
- Below 50,000/μL
- Below 20,000/μL (Correct answer)
- Below 100,000/μL
Correct answer: Below 20,000/μL
Platelet counts below 20,000/μL are associated with risk of spontaneous bleeding and often require prophylactic platelet transfusion.
Question 6: Heinz bodies in red blood cells are composed of:
- Iron deposits
- Denatured hemoglobin (Correct answer)
- DNA remnants
- Calcium crystals
Correct answer: Denatured hemoglobin
Heinz bodies are inclusions of denatured, precipitated hemoglobin, seen in G6PD deficiency and oxidative hemolysis.
Question 7: Which condition causes a decreased erythrocyte sedimentation rate (ESR)?
- Pregnancy
- Multiple myeloma
- Polycythemia vera (Correct answer)
- Rheumatoid arthritis
Correct answer: Polycythemia vera
Polycythemia vera decreases ESR because the increased RBC mass inhibits rouleaux formation and settling.
CMLA Hematology Basics 4
A reticulocyte count of 8% in a patient with hemolytic anemia indicates: