[Recent acquisitions concerning mediatinopulmonary sarcoidosis].

Sarcoidosis is a disease defined by two criteria: one quantitative involvement if several organs or tissues showing its systemic character) the other qualitative (presence in all affected organs of giant cell and epitheloid cell granulomas without caseation). The first seems to counter balance the absence of specificity of the second. Unfortunately, the quantitative factor may be lacking in the mediastino-pulmonary forms owing to their apparently localised character. The diagnosis is thus based on a critical study of the clinical context (age, general health radiological appearances) and indirect signs of diffusion (biopsies, immune reactions, Kweim test). The therapeutic indications should take into consideration the tendancy to spontaneous recovery which occurs in 98% of cases. Prolonged corticosteroid therapy may be difficult to stop. No treatment should therefore be given unless there are complications or associated lesions exposing the patient to the risk of severe and permanent sequelae.