Review Question - QID 207183

A 16-year-old male high school basketball player presents to his primary care provider with complaints of fatigue and night sweats for the past month. He also recalls that, after suffering a hand laceration during a game, the nurse had a difficult time achieving hemostasis. Otherwise, the patient has no other medical problems. Three weeks later, the patient is admitted to the ICU with decreased level of consciousness. Vital signs are: T 98.7 F, HR 110, BP 96/72, RR 18, SpO2 96%. CBC shows WBC 10, Hgb 9, Hct 35, and Plt 75. PT and PTT values are elevated. The following findings are seen on examination of the patient’s skin (Figure A). Peripheral blood smear reveals the following cell morphologies (Figure B). What is the underlying cause of this patient’s presentation?