Acute mesenteric ischemia (AMI) is a life-threatening vascular emergency characterized by compromised intestinal perfusion, often leading to bowel infarction if not promptly diagnosed. Mesenteric venous thrombosis (MVT), though less common than arterial causes, presents insidiously and is frequently associated with delayed diagnosis and high morbidity.

We report a case of a 54-year-old male presenting with progressive, poorly localized abdominal pain for 15 days, associated with melena and hematemesis. Clinical examination revealed diffuse abdominal tenderness with minimal peritoneal signs. Laboratory findings showed leukocytosis, anemia, elevated serum lactate, and mild renal dysfunction. Contrast-enhanced computed tomography (CECT) abdomen demonstrated dilated small bowel loops with reduced mural enhancement, pneumatosis intestinalis, mesenteric congestion, and inter-bowel free fluid. A non-enhancing intraluminal thrombus was identified within the superior mesenteric vein extending into the portal vein, consistent with extensive mesenteric venous thrombosis. Imaging features suggested non-viable bowel. Exploratory laparotomy confirmed transmural bowel gangrene, necessitating surgical resection.

Mesenteric venous thrombosis accounts for a minority of AMI cases but poses significant diagnostic challenges due to its subacute clinical course. CECT plays a pivotal role in early diagnosis by identifying venous thrombus, bowel wall hypoenhancement, mesenteric edema, and complications such as pneumatosis intestinalis. Recognition of these imaging features is critical for timely intervention and improved patient outcomes.

This case highlights the importance of maintaining a high index of suspicion for mesenteric venous thrombosis in patients with disproportionate abdominal pain and nonspecific findings. Multidetector CT is indispensable for early diagnosis, assessment of disease severity, and guiding management. Prompt radiologic identification of advanced ischemic changes can significantly impact prognosis in this potentially fatal condition