Intrathoracic omental herniation through the esophageal hiatus: a case report.

A case of paraesophageal omental herniation in a 74-year-old man is reported. Although computed tomography (CT) and magnetic resonance imaging (MRI) depicted a retrocardiac fatty mass that resembled omental herniation, residual concern remained regarding lipomatous tumor. Angiography provided decisive evidence of a mass containing omental vessels passing through the esophageal hiatus, which led to the final diagnosis. The patient underwent a strict course of observation, because he had no symptoms or abnormal physical or laboratory findings. Paraesophageal omental herniation mimics lipomatous tumors, such as lipoma or well-differentiated liposarcoma, extending to both sides of the diaphragm. Correct diagnosis of omental herniation requires the evidence of omental fat accompanied with omental vessels passing through the esophageal hiatus. Since angiography is an invasive diagnostic procedure, we would recommend dynamic MRI or reconstructed 3D MR angiography as alternatives to angiography.