'Downhill' esophageal varices. A rare cause of upper gastrointestinal bleeding.

The submucosal venous network of the esophagus is part of the collateral system that develops following superior vena caval obstruction from any cause. The direction of flow in these thin-walled, valveless veins is "downhill," towards the azygous vein or to the inferior vena cava. Bleeding from upper esophageal varices is extremely rare. This case report describes a patient with massive bleeding from upper esophageal varices secondary to superior vena caval obstruction by a malignant thyroid tumor. Total thyroidectomy relieved the obstruction, with cessation of hemorrhage and subsequent disappearance of the varices.