Retroperitoneal fibro-inflammatory disease · KIMS Secunderabad
Retroperitoneal Fibrosis — When Scar Tissue Around the Aorta Blocks the Ureters
Retroperitoneal fibrosis (RPF) — also called Ormond's disease — is a condition in which fibrous tissue proliferates in the retroperitoneum (the space behind the abdominal cavity), typically surrounding the abdominal aorta, the inferior vena cava, and the ureters. As the fibrotic mass enlarges, it encases and compresses the ureters, causing progressive ureteric obstruction, hydronephrosis, and — if bilateral — acute kidney injury or progressive CKD. The ureters are typically compressed and pulled medially toward the midline — the 'medial deviation of the ureters' on CT is a pathognomonic imaging finding.
Approximately two-thirds of RPF cases are idiopathic — no identifiable cause. A significant proportion of idiopathic RPF is now recognised as IgG4-related disease (see the KIMS IgG4 Nephropathy page) — with elevated serum IgG4 and IgG4-positive plasma cell infiltration of the retroperitoneal fibrotic tissue on biopsy. The remaining one-third are secondary RPF — from malignancy (periaortic lymphoma, retroperitoneal metastases from breast, lung, or colorectal cancer), certain drugs (methysergide, bromocriptine, beta-blockers — historical associations), prior aortic surgery or radiation, and abdominal aortic aneurysm (the inflammatory AAA variant).
Clinical presentation
Loin or flank pain — dull, constant, typically bilateral. The most common presenting symptom. Often mild and gradual in onset, attributed to musculoskeletal pain for months before the diagnosis is made.
Declining kidney function — from bilateral ureteric obstruction. May be the first clue when routine blood tests show rising creatinine without an obvious explanation.
Oliguria or anuria — in complete bilateral obstruction (uncommon at first presentation, but can develop if ureteric compression is severe and bilateral).
Constitutional features — in IgG4-related RPF: fatigue, low-grade fever, weight loss, elevated inflammatory markers (CRP, ESR, IgG4).
Hypertension — from compression of the renal arteries or from CKD-related mechanisms.
Deep vein thrombosis — compression of the inferior vena cava can impair venous return from the legs.
Diagnosis at KIMS
CT abdomen with contrast
The diagnostic investigation of choice. Shows the periaortic fibrotic mass (typically surrounding the infrarenal aorta and extending laterally), medial deviation and compression of the ureters (the medial deviation sign), bilateral hydronephrosis, and the degree of renal parenchymal preservation. The mass enhances with contrast in active disease and is characteristically periaortic and anterior — wrapping around the front and sides of the aorta without invasion of the aortic wall (which distinguishes RPF from malignant retroperitoneal tumours that typically invade structures).
MRI
Preferred over CT for IgG4-related RPF assessment (avoids contrast in patients with impaired eGFR from ureteric obstruction, and better characterises the fibrotic tissue composition — active inflammation shows high T2 signal, mature fibrosis shows low T2 signal, guiding steroid responsiveness prediction).
Serum IgG4 level and IgG4 biopsy
Elevated serum IgG4 (above 135 mg/dL) in IgG4-related RPF. CT-guided biopsy of the retroperitoneal mass — confirms the diagnosis (excluding malignancy) and identifies IgG4-positive plasma cell infiltration (IgG4/total IgG ratio above 40%, above 10 IgG4-positive cells per high-power field).
Ureteric stenting — urgent decompression when eGFR is compromised
Retrograde JJ stent insertion (or percutaneous nephrostomy if retrograde stenting fails) to relieve ureteric obstruction and protect kidney function while the fibrotic process is being treated. Stents may need to be changed every 3 to 6 months if long-term maintenance is required.
Treatment
Idiopathic or IgG4-related RPF — steroids
Prednisolone 40 to 60mg/day initially, tapering over 6 to 12 months. Steroids reduce the fibro-inflammatory mass, relieve ureteric compression, and restore kidney function in the majority of idiopathic and IgG4-related RPF. Serum IgG4 level, CT mass size, and ureteric obstruction degree are monitored during treatment. Tamoxifen (an anti-fibrotic agent) is an alternative or adjunct to steroids for maintaining remission in idiopathic RPF.
Surgical ureterolysis
For RPF not responding to steroids or presenting with severe bilateral obstruction requiring definitive relief — the ureters are surgically freed (ureterolysis) from the fibrotic encasement and, in some cases, transposed laterally to prevent re-encasement. Laparoscopic or open ureterolysis. The ureters may be wrapped in omentum to reduce risk of re-entrapment.
Treat secondary causes
Malignancy-related RPF: treat the primary tumour (chemotherapy, radiation). Drug-related RPF: stop the offending drug. Inflammatory AAA: aortic surgery or endovascular aneurysm repair may be combined with ureterolysis.
Book a Retroperitoneal Fibrosis Assessment at KIMS. Call 040-4488-5000
Frequently Asked Questions — Retroperitoneal Fibrosis
In approximately two-thirds of cases, RPF is idiopathic — no identifiable cause is found, and a proportion of these are now recognised as IgG4-related disease. Secondary causes include: retroperitoneal malignancy (lymphoma, metastatic cancer — the most important cause to exclude before treating with steroids, because steroids would mask the cancer), prior aortic surgery or radiation, the inflammatory variant of abdominal aortic aneurysm, and — historically — certain medications (methysergide, an ergot derivative used for migraine prevention, was a classic drug cause but is now largely withdrawn from clinical use). In India, TB is an important cause of retroperitoneal fibrosis and lymphadenopathy that can encase the ureters — TB must be excluded before starting steroids.
Yes — if bilateral ureteric obstruction from RPF is not relieved, the back-pressure causes progressive hydronephrosis, ischaemic damage to the renal parenchyma, tubular atrophy, and interstitial fibrosis — permanent CKD. The degree of kidney recovery after ureteric decompression (stenting, ureterolysis) depends on how long the obstruction has been present and how much parenchymal damage has already occurred. Early diagnosis and prompt decompression — while the kidneys are still functioning — gives the best chance of preserving kidney function. Long-standing bilateral obstruction with shrunken scarred kidneys on CT indicates a poor prognosis for kidney function recovery even after decompression.
The CT appearance of idiopathic RPF is characteristic: a periaortic soft tissue mass that wraps around the front and sides of the infrarenal aorta (anterior to it, but typically not engulfing it), pulls the ureters medially, and extends toward the pelvic brim. Malignant lymphoma or retroperitoneal metastases may appear similar but typically show: enlarged discrete lymph nodes rather than a homogeneous fibrotic sheet, encasement or displacement of the aorta (rather than anterior wrapping), and often irregular margins. CT-guided biopsy is the definitive test — it confirms the diagnosis and excludes malignancy before steroids are started. Biopsy also identifies IgG4-positive plasma cells, confirming IgG4-related RPF.
Yes — steroids are the primary treatment for idiopathic and IgG4-related RPF. The fibro-inflammatory mass responds to prednisolone within weeks — the mass shrinks (visible on serial CT), ureteric compression reduces, and kidney function improves as hydronephrosis resolves. The response is most dramatic in early, active IgG4-related RPF (where the mass is highly cellular with inflammatory infiltration) and less so in longstanding fibrotic RPF (where mature collagen has replaced the cellular tissue and is less steroid-responsive — the MRI T2 signal predicts this: low T2 = mature fibrosis = poor steroid response). Long-term maintenance with low-dose prednisolone or tamoxifen reduces relapse rates.
KIMS Secunderabad — Dr. K. V. R. Prasad (Chief Urologist, 28+ years, ureterolysis) and Dr. E. Ravi (Senior Nephrologist, kidney function monitoring), CT abdomen for diagnosis and monitoring, serum IgG4, CT-guided biopsy, retrograde ureteric stenting for urgent decompression, prednisolone protocol, laparoscopic ureterolysis for steroid-refractory cases, TB exclusion before steroids. NABH and NABL accredited. Call 040-4488-5000.