[The liver herniation through four diaphragmatic defects, simulating lobulated diaphragmatic tumor]

A 47 year-old woman, 153 cm in height and 64 kg in weight, was admitted for investigation of mass like shadow of the right lower lung field without past history of trauma and surgical treatment While magnetic resonance imaging (MRI) showed a mass 3 cm in diameter having the running vessel from the liver, computed tomography (CT) scan showed that the mass was lobulated like a tumor. We therefore performed video-assisted thoracic surgery (VATS) for diagnosis, which revealed the 4 lobulated liver tissues protruding through 4 defects of the diaphragm. The herniated parts of the liver were replaced in the abdominal cavity and diaphragmatic defects repaired by VATS. At histological features of diaphragm, thinning muscle layer was observed without any specific findings. We speculated that weakening of diaphragm was a cause of herniation.

Liver herniation through multiple defects is sometimes difficult to be differentiated from diaphragmatic tumors. VATS is not only useful to diagnose it but also to repair the defects.