[Two cases of Morgagni's hernia]

Two cases of Morgagni's hernia comprising protrusion of the omentum alone are reported. The treated patients were 65- and 63-year-old obese women. They were referred to our hospital because of chest pain or vomiting accompanied by abnormal shadow in right cardiophrenic angle on chest roentgenogram. Computed tomogram (CT) demonstrated a mass of fat density behind the sternum for the both patients. The first patient was diagnosed as Morgagni's hernia by pneumoperitoneum, and surgical repair was done by the transabdominal approach. Magnetic resonance imaging (MRI) was carried out for the second patient, and showed intrathoracic mass lesion which was continuous with the subphrenic tissue. Although the second patient was diagnosed as mediastinal lipoma, median sternotomy revealed that the mass lesion was Morgagni's hernia. Postoperatively, both patients recovered uneventfully. The Morgagni's hernia has been reported to be about 3% of all diaphragmatic hernia. This disease may be discovered either because it causes respiratory or gastrointestinal complaints, or because an abnormal shadow in right cardiophrenic angle on a chest roentgenogram. If air-filled structures are present in the hernia, a barium study will confirm the diagnosis. In a case with a hernia containing only omentum, the diagnosis is difficult. CT has been regarded as the procedure of choice by several authors. The coronal and sagittal views of MRI can demonstrate the relationship between the herniated structures and the diaphragm, heart, pericardium. We emphasize the role of MRI for the diagnosis of Morgagni's hernia.