A Young Man with Hematemesis.

Primary aortoenteric fistula (AEF) is a rare but fatal cause of upper gastrointestinal bleed. A 27-year-old previously healthy man presented with massive hematemesis, melena, severe anemia and hemodynamic instability. Point-of-care ultrasound and chest radiography suggested thoracic aortic pathology, and CT aortography confirmed a descending thoracic aneurysm with contained rupture and fistulous communication with the esophagus. This case highlights the need to consider rare vascular causes in massive hematemesis, where early imaging can facilitate rapid diagnosis and timely intervention.