Superior Mesenteric Vein and Portal Vein Thrombosis in an Immunocompetent Patient With Acute Cytomegalovirus Infection

Cytomegalovirus (CMV) infections are common worldwide, with clinical manifestations varying from asymptomatic infections in healthy people to life-threatening end-organ dysfunction in immunocompromised patients. Acute CMV infection has been associated with venous thrombosis in immunocompetent patients. We present a rare case of acute superior mesenteric vein (SMV) and portal vein thrombosis in an immunocompetent patient with acute CMV infection. A 28-year-old patient with a past medical history of obesity presented with two days of sharp, 9/10 left upper quadrant (LUQ) pain that radiated to the back, associated with subjective fevers, nausea, and loose stools. The patient was tachycardic, febrile, and tachypneic. Physical examination revealed LUQ tenderness to superficial and deep palpation. Laboratory findings showed leukocytosis with lymphocytic predominance as well as transaminemia. CT of the abdomen/pelvis revealed SMV and portal vein thrombosis, hepatomegaly, and splenomegaly with multiple splenic infarcts. The thrombophilia workup was negative. CMV testing showed positive IgM. CMV polymerase chain reaction was elevated at 1,222 log IU/mL. He was started on ganciclovir and improved clinically. He was discharged on oral ganciclovir and warfarin. This case report emphasizes that, in an immunocompetent patient presenting with acute deep vein thrombosis at unusual sites, a negative thrombophilia workup, and after excluding other risk factors, CMV infection as a triggering etiological factor should be considered.