Spontaneous atraumatic splenic rupture secondary to infectious mononucleosis.

Presentation: A healthy 23-year-old man developed sore throat and fever with positive EBV Infectious Mononucleosis test, followed by abdominal pain, vomiting, and haemodynamic collapse, without trauma. Diagnosis: Bedside ultrasound suggested intraperitoneal free fluid. Urgent contrast-enhanced CT demonstrated large haemoperitoneum, perisplenic and subcapsular haematoma, and active splenic contrast extravasation. Treatment: Emergency laparotomy revealed massive haemoperitoneum, and confirmed splenic bleeding; splenectomy was performed. Recovery was uncomplicated, with post-splenectomy antibiotics and vaccinations. He was well at three-month follow-up. Discussion: EBV-associated atraumatic splenic rupture is rare yet life-threatening. CT imaging confirms injury and bleeding. Management depends on physiology; unstable patients require prompt surgical management, whereas stable cases may merit spleen-preserving strategies and close monitoring.