Examkin

Question

Difficulty: MediumHematology and Oncology

Match each patient's clinical presentation with the most likely corresponding finding on a peripheral blood smear.

  • A 54-year-old asymptomatic man with an incidentally discovered leukocyte count of 65,000/mm365,000/\text{mm}^3 (predominantly mature-appearing small lymphocytes) and bilateral painless cervical lymphadenopathy.Smudge cells (fragile, disrupted leukocytes)
  • A 23-year-old Mediterranean man with lifelong mild, asymptomatic microcytic anemia, normal iron studies, and an elevated hemoglobin A2A_2 fraction.Target cells (codocytes with central hemoglobin concentration)
  • A 31-year-old man who develops scleral icterus, dark urine, and a rapid drop in hemoglobin two days after initiating trimethoprim-sulfamethoxazole for a skin infection.Bite cells (degmacytes with semicircular peripheral defects)
  • A 72-year-old woman presenting with progressive fatigue, a mean corpuscular volume of 118 fL118 \text{ fL}, and new-onset loss of vibratory sensation in her lower extremities.Hypersegmented neutrophils (multilobated nuclei)

Answer

Chronic Lymphocytic Leukemia pairs with smudge cells; beta-thalassemia trait pairs with target cells; G6PD deficiency pairs with bite cells; and Vitamin B12 deficiency pairs with hypersegmented neutrophils.
Each peripheral smear finding is generated by a specific mechanism unique to the paired disease: mechanical disruption of fragile B-cells (smudge cells in CLL), relative membrane excess (target cells in thalassemia), splenic macrophage pitting of Heinz bodies (bite cells in G6PD deficiency), and impaired DNA synthesis delaying nuclear lobation (hypersegmented neutrophils in Vitamin B12 deficiency).

Step-by-Step Solution

1
Diagnose the underlying condition for each clinical vignette.
Vignette 1 is Chronic Lymphocytic Leukemia (CLL). Vignette 2 is beta-thalassemia minor. Vignette 3 is G6PD deficiency. Vignette 4 is Vitamin B12 deficiency.
Accurate diagnosis is required before associating the pathophysiologic mechanism with its corresponding smear finding.
2
Recall the mechanism of red or white blood cell morphologic changes in each identified condition.
CLL involves fragile neoplastic lymphocytes. Beta-thalassemia involves decreased hemoglobin synthesis resulting in relative membrane excess. G6PD deficiency involves oxidative denaturation of hemoglobin. B12 deficiency involves impaired DNA synthesis.
Understanding the mechanism explains the physical appearance of the cells under microscopy.
3
Map the mechanism to the specific named peripheral smear finding.
Fragile lymphocytes = smudge cells; membrane excess = target cells; pitted Heinz bodies = bite cells; delayed nuclear maturation = hypersegmented neutrophils.
This completes the pairing for the final answer.

Key Concept

Peripheral blood smear findings reflect specific underlying pathophysiologic mechanisms in hematologic disorders.
Estimated Time:1m 30s
Rate this question

Topics

Hematology and Oncology

More questions from this topic