The authors declare that they have no competing interest.
SF performed the ultrasound scan, researched the cost-benefit analysis based on medicare prices, researched the association of mononucleosis and splenomegaly, and drafted the manuscript. CF supervised and reconfirmed the ultrasound scan, participated in the cost benefit analysis research, and helped draft the manuscript. Both authors read and approved the final manuscript.
Currently, infectious mononucleosis (IM) is a clinically diagnosed condition. According to the American Family Physician criteria for IM, splenomegaly is the key factor that distinguishes IM from other causes of sore throat. Though heterophile antibody tests are often ordered to confirm diagnosis of IM, this test has a high false-negative rate early in the course of the disease. This case report provides an example of how the use of ultrasound to diagnose splenomegaly and subsequently mononucleosis increases diagnostic accuracy.