Abstract
A man in his 60s visited the emergency department because of epigastric pain and vomiting. Noncontrast helical abdominal CT revealed a lipomatous mass on the right side of the lower esophagus. Caudal slices showed that the mass appeared to displace the gastric antrum causing gastric outlet obstruction. Further observation revealed a linear structure from the greater curvature of the stomach into the omental vessels. Based on these findings, a diagnosis of intrathoracic omental hernia through the esophageal hiatus was made. Intraoperatively, a defect in the lesser omentum was seen, and the greater omentum herniated through the defect into the esophageal hiatus. Omental herniation through the lesser omentum into the esophageal hiatus can present as gastric outlet obstruction.