Retroperitoneal Fibrosis

Key points

• Retroperitoneal fibrosis (RPF) is a fibro-inflammatory process that can encase the ureters and cause obstructive uropathy. Back/abdominal/flank pain can occur, but it is not correct to state that lower-back/flank pain is invariably the most common presentation; symptoms are variable.
• Previous radiotherapy is a recognised secondary association of RPF; other causes/associations include malignancy, drugs and IgG4-related disease.
• Inflammatory abdominal aortic aneurysm is a recognised association with RPF.
• MRCP discriminator: obstructive renal impairment/hydronephrosis + periaortic retroperitoneal mass + back/abdominal pain → RPF.
• Modern association: IgG4-related disease is an important cause of otherwise idiopathic-pattern RPF.