Ectopic varices represent 1–5% of variceal bleeding and carry a high mortality rate. Duodenal varices are more frequent in extrahepatic portal hypertension, often related to prior abdominal surgery. Diagnosis requires high suspicion and use of imaging when endoscopy is inconclusive. Treatment involves endoscopy, interventional radiology, or surgery, depending on the case. We report the case of a 37-year-old woman who presented with upper gastrointestinal bleeding due to ectopic duodenal varices, revealing extrahepatic portal hypertension with a portal cavernoma. Diagnosis was made through endoscopy and imaging. Despite endoscopic and surgical treatment, the outcome was fatal. This case highlights the severity and management challenges of ectopic varices. This case illustrates the severity and diagnostic difficulty of ectopic varices and the need for a multidisciplinary, tailored approach to improve outcomes. Early diagnosis and timely treatment are critical to reduce mortality.