A 23-year-old male presented in the emergency department of a district general hospital with an acute onset of left upper quadrant abdominal pain and a syncopal episode one hour prior to his admittance. Abdominal pain had a sudden outburst while the patient was resting at home, and there was no indication of trauma history. The patient reported one-week history of fever up to 40 C, sore throat, and malaise, as well as oral consumption of 5 to 8 tablets of 500 mg of acetylsalicylic acid within the two previous days. On initial examination he was in shock, pale, tachycardic with a heart rate of 110 beats per minute, tachypnoeic and hypotensive with a blood pressure of 90/60 mm Hg, and a fever of 38.5  C. Physical examination revealed bilateral nontender cervical lymphadenopathy and diffuse abdominal guarding with rebound tenderness. Kehr's sign was also positive. Admission laboratory tests revealed a WBC count of 17.000 cells/muL with 53% atypical lymphocytes while the value of Hb was 9 g/dL. The patient's platelet count was normal (170.000/muL), prothrombin time (PT) was 13.8 sec (reference time: 13 sec), international normalized ratio (INR) was 1.06, and activated partial thromboplastin (aPTT) time was 30.6 sec (normal: 28-40 sec). Serum transaminases were slightly elevated with an ALT 152 U/L and AST 138 U/L. The patient's history of fever, lymphadenopathy, sore throat, atypical lymphocytosis combined with his clinical presentation of peritonitis, and hypotension in the absence of a trauma incidence was suggestive of a possible diagnosis of spontaneous splenic rupture on the basis of the underlying IM.
 After initial resuscitation with 3 liters of intravenous crystalloids, an emergency abdominal CT was carried out to confirm the diagnosis. CT showed a large splenic hematoma and large amounts of fluid in all four abdominal quadrants and in the pelvis (Figure 1). An exploratory laparotomy was undertaken. During laparotomy, there was a notable amount of fresh and clotted blood in the abdomen while the spleen was large and congested. It had a 5 cm capsular tear near the hilum and a large subcapsular hematoma. The enlarged, friable spleen was almost completely devoid of capsule. We performed an uncomplicated splenectomy, and after a thorough lavage of the peritoneal cavity, no other abnormal findings were revealed. The patient returned to the surgical ward hemodynamically stable, and no blood transfusion was necessary. Pathologic examination revealed an enlarged spleen 15 x 7 x 5 cm, weighing 430 gr. Microscopic examination accented an expanded red pulp and moderate follicular hyperplasia. The diagnosis of IM was later confirmed by the presence of IgM antibodies to Epstein-Bar virus capsid antigen (VCA). The patient recovered uneventfully and was discharged on the 7th postoperative day.