Melena and Silent Mesenteric Ischemia: Portomesenteric Thrombosis without Tenderness

Acute mesenteric venous thrombosis is an uncommon but potentially fatal cause of mesenteric ischemia, whose nonspecific presentation can delay diagnosis. We report a 46-year-old man with no prior thromboembolic, hepatic, or malignant disease who presented with five days of periumbilical pain, vomiting, and melena. Upper endoscopy revealed hematin without an identifiable bleeding source. Computed tomography angiography revealed extensive portal, splenic, and superior mesenteric venous thrombosis with jejunal ischemia. Intravenous heparin was started, and the patient was monitored closely because his abdomen remained soft and non-tender. After approximately 48 hours, he developed sudden hemodynamic collapse; emergency laparotomy revealed 100 cm of necrotic jejunum, which was resected without primary anastomosis. Despite intensive postoperative support, he died of cardiovascular collapse approximately 24 hours later. This case shows that extensive portomesenteric thrombosis can cause severe and fatal intestinal ischemia despite reassuring abdominal findings, underscoring the need for prompt imaging, anticoagulation, and vigilant reassessment.