Case: We report a rare case of omental herniation through the esophageal hiatus. A 46-year-old man visited our emergency department complaining of epigastralgia. Abdominal examination revealed muscular defense and rebound tenderness in his upper abdomen. A computed tomography scan showed a fat density mass in the posterior mediastinum. A laparoscopic operation was carried out under the diagnosis of omental herniation through the esophageal hiatus.
Outcome: Abdominal pain disappeared dramatically after the operation. The postoperative course was uneventful.
Conclusion: Although a fat density mass in the posterior mediastinum is likely to be diagnosed as a lipomatous tumor, omental herniation through the esophageal hiatus should be taken into consideration as a possible diagnosis for acute abdominal pain in the emergency department.
Keywords: CT; laparoscopy; mediastinum; omental herniation; paraesophageal hernia.