[Superior mesenteric venous thrombosis during treatment of malignant lymphoma and of pure red cell aplasia].

Mesenteric vein thrombosis is an uncommon type of intestinal ischemia that can be associated with significant mortality if its diagnosis is delayed. We experienced two patients with hematological disorders--non-Hodgkin's lymphoma (NHL) and pure red cell aplasia (PRCA)--who developed superior mesenteric vein (SMV) thrombosis during treatment. Neither of the patients had underlying disorders of the anticoagulant system that might have produced a hypercoagulable state. The first patient developed SMV thrombosis immediately after chemotherapy for NHL. This patient also had portal hypertension due to chronic hepatitis B. Direct injury to endothelial cells by the anti-cancer drugs and alteration of blood flow were the probable causes of the SMV thrombosis. The second patient with PRCA had regularly taken prednisolone, and this had induced a hypercoagulable state. The clinical symptoms of SMV thrombosis are usually non-specific, and in our patients vague, crampy abdominal pain without bloody diarrhea was the only complaint. Abdominal CT scan under a clinical suspicion of SMV thrombosis revealed the thrombi in the SMV. Urgent surgical resection of the infarcted bowel and immediate postoperative anticoagulation resulted in a favorable outcome. Clinicians should be aware of the vague symptoms of SMV thrombosis, as early diagnosis and urgent therapy are essential to prevent a fatal outcome.