[Chronic idiopathic fibrous mediastinitis]

We present two cases of idiopathic mediastinal fibrosis. Morphological study disclosed the presence of fibrosis, granulomas and an inespecific inflamatory infiltration. Because this morfological pattern, the entity has been confused with Hodgkin's disease, tuberculosis, hystoplasmosis and silicosis. Idiopathic mediastinal fibrosis is probably a fibromatosis and the amount of inflammatory infiltration dependes of the clinical stage.