Pulmonary Hemorrhage Secondary to Superior Vena Cava Thrombosis Mimicking Upper Gastrointestinal Bleeding: A Case Report.

Upper gastrointestinal bleeding (UGIB) is a frequent cause of emergency department admission and is most commonly attributed to peptic ulcer disease or portal hypertension-related varices. In critically ill patients, however, pulmonary bleeding may be misinterpreted as hematemesis when blood is swallowed or expelled during retching or airway compromise. In patients undergoing long-term hemodialysis, catheter-related central venous thrombosis can precipitate atypical bleeding presentations. We report the case of a 45-year-old man with chronic kidney disease on maintenance hemodialysis who presented with sudden-onset recurrent hematemesis and hemodynamic instability. Initial evaluation suggested severe UGIB, prompting endotracheal intubation, vasopressor support, and urgent upper endoscopy. Endoscopy demonstrated small esophageal varices and erosive gastropathy without evidence of active bleeding. Subsequent chest computed tomography revealed superior vena cava thrombosis with extensive mediastinal collateral circulation and imaging findings consistent with pulmonary hemorrhage. Bronchoscopy confirmed active bleeding originating from the right bronchial tree, establishing the diagnosis of pulmonary hemorrhage secondary to superior vena cava thrombosis. This case underscores an important diagnostic pitfall: severe pulmonary hemorrhage may mimic UGIB, particularly when initial endoscopic evaluation is non-diagnostic. In hemodialysis patients, superior vena cava thrombosis and collateral vessel formation should be considered as potential mechanisms of airway bleeding even in the absence of classic superior vena cava syndrome. Early thoracic imaging and bronchoscopy are essential when endoscopic findings do not account for persistent or severe hematemesis to prevent diagnostic delays and inappropriate gastrointestinal interventions.