A 28-year-old man presented to the emergency department with acute left upper quadrant tenderness and postural hypotension. He reported having had fever and cervical tenderness for 1 week before his presentation.
Blood tests showed an elevated white cell count with reactive lymphocytosis. A test for infectious mononucleosis heterophile antibody was positive, consistent with recent infection.
A contrast scan of the abdomen showed splenomegaly with subcapsular haematoma.