A 41-year-old woman was evaluated for a 5-month history of dyspnea and cardiac arrhythmia. Chest radiography revealed an enlarged right mediastinum with air content on the right side (Panel A, arrow; and Panel B, lateral view). Thoracic computed tomographic (CT) scans showed a Morgagni's hernia, characterized by an anteromedial diaphragmatic defect, with herniation of the transverse colon and part of the omentum into the thorax (Panels C and D).
CT scans also showed that the bowel contents were compressing the right side of the heart.
Morgagni's hernias are secondary to congenital defects in the anterior diaphragm. The hernia sac frequently contains the transverse colon with the omentum; more rarely, the stomach, small bowel, or liver is involved. The patient's hernia was laparoscopically reduced , and the diaphragmatic defect was repaired with a composite mesh. Postoperatively, the patient's symptoms resolved. Follow-up thoracic CT confirmed the absence of bowel contents in the thorax.
