38-year-old man who recently emigrated from Eastern Europe comes to the physician with a 2-month history of
exertional shortness of breath and easy fatigability. He has been taking isoniazid for latent tuberculosis for the last
5 months. He also became a vegan 5 months ago. Physical examination shows severe conjunctiva! pallor and
areas of depigmentation on his arms suggestive of vitiligo. His tongue appears shiny. The spleen is not palpable.
Laboratory results are as follows:
Hemoglobin 6.5 g/dL
Mean corpuscular volume 110 fl
White blood cells 4,100/mm3
Platelets 135,000/mm3
Which of the following is the most likely diagnosis?
- O A. Chronic myeloid leukemia
- 0 B. Dietary vitamin 812 deficiency
- 0 C. lsoniazid toxicity
- O D. Myelodysplastic syndrome
- 0 E. Pernicious anemia
0 voters