[Retroperitoneal fibrosis].

Neoplastic and non-neoplastic retroperitoneal fibrosis share the same macroscopic and histological features and the same clinical signs which mainly consist of abdominal pain followed by signs of compression. All carry a risk of extension to adjacent structures and may therefore produce serious complications. They may also be associated with a "systemic" syndrome with fever, altered general condition and high erythrocyte sedimentation rate. The necessary laboratory and radiological examinations are detailed. Non-neoplastic retroperitoneal fibrosis may be due to a variety of causes, the most frequent of which today are medications and aortic atheroma. Surgery is usually needed when the disease is life-threatening or of poor functional prognosis. Some authors have suggested that surgery should be combined with corticosteroid therapy. In some cases, regression of the fibrosis could only be obtained by giving steroids in high doses.