[How can the extension of lung cancer to the osteo-muscular wall of the diaphragm, the pleura and the apex be assessed radiologically?].

The merits of evaluating the parietal extension of lung cancers is emphasized by the new TNM classification. CT and MRI have added to the conventional radiological techniques. The authors successively analyze the contribution of these techniques to the assessment of extension of lung cancers to the wall, including the costal and phrenic compartments, to the pleura and to the apex. Lung radiographs show obvious lesions, such as extensive costal lysis and major pleural extensions. Computed tomography has better sensitivity and specificity than lung radiographs to establish pleuroparietal involvement; it is best performed in the inclined plane of the ribs and in the high-resolution mode. The presence of costal lysis means parietal involvement, while the integrity of the pleura can be established if the lesion remains at a distance from the wall. The persistence of an extrapleural fatty rim between the tumor and the wall allows ruling out parietal extension. MRI provides accurate details in case of doubtful CT findings for the extension to the costovertebral groove, to the intervertebral foramina, to the peridural space and to the diaphragm. Its major asset is to assess the vertebral, vascular and nervous extension of cancers of the apex pulmonis.