<prompt> An 18-year-old woman visits her physician because of 3 weeks of malaise, 2 weeks of fever, and a sore throat. Physical examination shows pharyngeal infection with enlarged tonsils and a patchy, white exudate; enlarged, palpable anterior and posterior cervical, axillary, and inguinal lymph nodes; tenderness in the right upper quadrant; and minimal splenomegaly. Laboratory data show hemoglobin 14 gdL; hematocrit 42; platelets 380,000mL; WBC 8500mL, with 35 segmented neutrophils, 1 eosinophils, and 64 lymphocytes, of which 36 were atypical. Which of the following is the most likely diagnosis?infectious hepatitislymphocytic leukemiainfectious mononucleosisHodgkins disease  <response>: Infectious mononucleosis is an acute, self-limited infection of the lymphatic system by the EBV. Typical infectious mononucleosis has an incubation period of 4-8 weeks. The prodrome includes malaise, anorexia, and chills, and then the classic symptoms of pharyngitis, fever, and lymphadenopathy develop. Headache is also common. 