Idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (IRF) is a subtype of retroperitoneal fibrosis where no obvious cause is found. It includes a spectrum of diseases which are characterized by fibroinflammatory tissue encasing the abdominal aorta and the iliac arteries. This process may extend into the retroperitoneum often enveloping the adjacent structures e.g. ureters. 

Retroperitoneal fibrosis in general is an uncommon condition with an estimated incidence of about 1.38 cases per 100,000 people 1; of these ~70% cases are idiopathic.

This inflammatory pathology is thought to arise as an autoimmune response to ceroid which leaks out of the atherosclerotic plaques and causes vasculitis. It is seen in association with other autoimmune processes, suggesting the possibility of an underlying autoimmune pathology.

Reported associations include

Contrast-enhancing fibrosis encompassing the retroperitoneal structures causing ureteric and vascular obstruction and displacement is seen with no other demonstrable alternative conditions or malignancy.

Complications such as acute renal failure secondary to periureteral involvement require prompt intervention. Treatment usually involves corticosteroids with or without other immunomodulating medications or tamoxifen. In the presence of periureteral or perivascular involvement, surgical intervention may be necessary.

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Article information

rID: 25643
Synonyms or Alternate Spellings:
  • Primary retroperitoneal fibrosis
  • Idiopathic retroperitoneal fibrosis (IRF)

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