USMLE® Step 1 style questions USMLE
A 56-year old Caucasian man comes to the emergency department because of severe fatigue, mild fever, and lightheadedness. His medical history is relevant for a very recent hospitalization. Upon further revision of his medical records, you find out that the patient was discharged from the hospital 2-days ago because of a resolved gastrointestinal infection. On physical examination, the patient is pale and has mild splenomegaly. His temperature is 37.8°C (99.6°F), pulse is 102/min, respirations are 26/min, and blood pressure is 110/60 mmHg. Laboratory studies show increased leukocytosis (50,000/mm3) with increased neutrophilic precursor dominance and increased leukocyte alkaline phosphatase. Bone marrow aspiration is hypercellular but otherwise unremarkable. Which of the following is the most likely diagnosis?