[Retroperitoneal fibrosis and chronic peri-aortitis--new hypothesis]

Retroperitoneal fibrosis is characterised by the development of fibrotic mass surrounding the abdominal aorta and its branches. In the one third of cases, the causes of this disease include ergot-derivative drugs, retoperitoneal haemorrhage or urine extravasation and desmoplastic response to a variety of tumours. Retroperitoneal fibrosis is idiopathic in two thirds of cases and is found most commonly as an isolated fibrotic plague centered over the lumbar spine and entrapping one or both ureters. It has been postulated that fibrosis in idiopathic cases is caused by a chronic inflammatory or autoimmune response to antigens leaking into retroperitoneum from atheromatous plagues in the aorta or common iliac arteries. Many findings indicate the active nature of aortic adventitial chronic inflammation associated with human advanced atherosclerosis ("chronic periaortitis") and show its possible progressive potential to the clinically important disease termed "idiopathic retroperitoneal fibrosis" and "inflammatory aneurysm". A definitive differential diagnosis requires not only CT and NMR but also histologic confirmation. Treatment may be surgical or medical, with the best outcome observed in patient receiving both.