[Portal-splenic-mesenteric venous thrombosis secondary to a mutation of the prothrombin gene].

Thrombosis of the portal-mesenteric axis is an infrequent cause of intestinal ischemia or infarction. In addition to the multiple acquired factors that contribute to the development of this entity, hereditary risk factors, especially the factor V Leiden mutation and the G20210A mutation of the prothrombin gene, have been implicated. The G20210A mutation of the prothrombin gene is found in up to 40% of patients with splenic-portal-mesenteric thrombosis. The present case illustrates the unusual and nonspecific presentation of this mutation in the form of diarrhea and images of thrombosis of the superior mesenteric-portal vein and cavernous transformation of the portal vein. Delayed diagnosis is highly frequent since the clinical signs, laboratory investigations and radiological tests do not suggest the diagnosis. The patient received anticoagulant treatment and showed clinical improvement with complete portal-mesenteric recanalization. Currently the diagnostic technique of choice is magnetic resonance angiography or computerized tomography angiography and treatment consists of indefinite anticoagulation. This case illustrates that an unusual or atypical localization of venous thrombosis may be a manifestation of thrombophilia, emphasizing the importance of genetic screening in these cases.