Hematologic Malignancies USMLE Step 1 Practice Question
A 48-year-old man presents with fever (38.9°C), productive cough, and dyspnea. Examination reveals left lower lobe consolidation on chest X-ray. Vital signs show BP 138/82, HR 108, RR 22, SpO2 92% on room air. Labs demonstrate WBC 42,000/mm³ with left shift (mature and band neutrophils predominate), normal basophils, and elevated leukocyte alkaline phosphatase score of 85. He denies recent chemotherapy or hematologic disorders. Which diagnosis best explains these findings?
Answer choices
- APrimary myelofibrosis
- BAcute promyelocytic leukemia
- CPolycythemia vera
- DLeukemoid reaction due to severe infectionCorrect answer
- EChronic myelogenous leukemia
- FAcute myeloid leukemia with monocytic differentiation
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