[Evaluation of the extent of intra-thoracic lymph nodes. Role of mediastinoscopy].

Mediastinoscopy is a technique which enables palpation, inspection and biopsy of superior mediastinal glands. When this examination is done routinely in patients suffering from lung cancer which is presumed to be operable, 25-30% are found to have a positive gland and the greater part of these individuals become inoperable on account of significant invasion. The specificity of mediastinoscopy is 100% and this specificity ensures that no potentially operable patient would be refused a surgical cure. Anterior mediastinoscopy and an extended cervical mediastinoscopy are complementary techniques which enable the anterior mediastinum to be explored in patients suffering from cancer of the left upper lobe. In experienced hands, these techniques are safe and lead to little or no morbidity.