Morgagni Hernia

Anterior hernias of the foramina of Morgagni are very rare, result from failure of fusion of the septum transversum with the body wall, and usually present later in life. Morgagni hernias are most often in the right side, because left herniation is prevented by the heart and pericardium. These hernias are mostly asymptomatique, although lower sternal discomfort, cough, dyspnea and non-specific gastrointestinal symptoms may occur. Imaging features vary depending on the herniated contents that include omentum, liver, or colon. On chest radiography, they typically appear as a well-defined opacity in the right cardiophrenic angle. Air-containing loops of small or large bowel are occasionally seen. The diagnosis of Morgagni hernia can be readily made on CT or MRI (Fig).

Fig: MORGAGNI HERNIA

An asymptomatic 35-year-old man A. Routine chest radiograph: homogeneous regular mass obscuring right and left cardiophrenic angle mimicking cardiomegaly. B. CT scan: huge fatty density mass containing vascular structures in the left lower chest and precardiac area. C. Sagittal and D. Coronal contrast-enhanced T1-weighted MRI with fat suppression: small defect (arrows) of the anterior part of the diaphragm with herniated omental fat.