[Liver herniation simulating a benign lung tumor].

A 49-year-old woman complained of coughing and sputum production a mass shadow was seen in the right lower lung field on a chest radiography. The shadow was first suspected to represent a benign lung tumor, because of its clear margin and narrow pedicle. After detailed examination liver herniation was suspected, since the CT number of the tumor was similar to that of the liver. Liver herniation was finally confirmed by chest MRI, liver scintigraphy and angiography of the abdomen. Liver herniation should be differentiated from an intrathoracic mass in the right lower lung field.