[Constriction of liver tissue herniated through a diaphragmatic defect, simulating a pulmonary tumor].

Defects in the dome of the right diaphragm are a rarity among diaphragmatic abnormalities. Here we report the case of an elderly man who presented with an intrathoracic nodular opacity adjacent to the right diaphragm on chest radiographs. A radionuclide liver scan and maximum intensity projection (MIP) images of a computed tomographic (CT) scan together yielded a diagnosis of diaphragmatic defect with herniation of liver tissue. The herniated liver was so constricted that the angle made by the nodule and diaphragm became acute, resulting in close resemblance to a pulmonary tumor. This unusual configuration of herniated liver tissue was reviewed and the cause of constriction and diagnostic procedure were discussed. To avoid unnecessary examinations, herniation of liver tissue should be included in the differential diagnosis of intrathoracic nodular opacities, particularly when they are in contact with the diaphragm.