Retroperitoneal Fibrosis: Symptoms, Risks, and Treatment

Quick heads-up: This article is for education, not a diagnosis. Retroperitoneal fibrosis (RPF) is rare, but its complications can be seriousso if anything here sounds familiar, it’s worth bringing to a clinician sooner rather than later.

Retroperitoneal fibrosis is one of those conditions that can feel like your body quietly rearranged the furniture in your abdomen… and forgot to tell you. It often starts with vague back or flank pain, maybe fatigue, maybe some “why do I feel off?” symptoms. Meanwhile, scar-like tissue can slowly form behind the lining of the abdominal cavity (the retroperitoneum) and begin squeezing nearby structuresespecially the ureters (the tubes that drain urine from kidneys to bladder). When the ureters get pinched, urine backs up, pressure rises, and kidneys can take the hit.

The good news: with early detection and the right treatment plan, many people improve significantly and protect kidney function. The tricky part is recognizing it early enoughbecause RPF doesn’t always show up with a dramatic entrance. More like a suspense movie where the villain is a quiet fog rolling in.

What Is Retroperitoneal Fibrosis (RPF), Exactly?

The retroperitoneum is the space in the back of your abdomen that houses major “infrastructure” items: kidneys, ureters, the abdominal aorta, vena cava, and lymphatic structures. In RPF, fibroinflammatory tissue develops in this areaoften around the abdominal aorta and iliac vesselsand can spread outward like a tightening wrap.

RPF is sometimes called Ormond’s disease (especially when it’s idiopathic, meaning the cause isn’t clearly identified). Clinically, doctors often think of RPF in two broad buckets:

• Idiopathic (primary) RPF: No single obvious trigger is found; immune-mediated inflammation is thought to play a central role.
• Secondary RPF: Scar tissue develops in association with another factor (certain medications, malignancy, infection, radiation, surgery, inflammatory conditions, etc.).

A major modern insight: a meaningful portion of “idiopathic” cases overlap with IgG4-related disease (IgG4-RD), an immune condition that can cause mass-forming inflammation and fibrosis in multiple organs.

Symptoms of Retroperitoneal Fibrosis

RPF symptoms depend on what is being compressed and how much. Early symptoms are often nonspecificone reason diagnosis can be delayed.

Common early symptoms

• Dull pain in the lower back, flank, abdomen, or groin (sometimes hard to pinpoint)
• Fatigue or low energy
• Unexplained weight loss or reduced appetite
• Low-grade fever or “inflammation” feelings

Symptoms tied to ureteral obstruction and kidney stress

• Decreased urine output (or changes in urination patterns)
• Swelling (fluid retention) in some cases
• Nausea, poor appetite, or general illness if kidney function worsens
• High blood pressure can occur, sometimes discovered incidentally

Symptoms tied to blood vessel/lymph compression

• Leg swelling, leg pain, or color change (from venous/lymphatic compression)
• Scrotal swelling or testicular pain in some men
• Difficulty moving legs (less common, but reported when structures are compressed)

Important: Some people have minimal symptoms until kidney obstruction becomes significant. That’s why persistent flank/back pain plus abnormal kidney labs is a combination clinicians take seriously.

What Causes RPF? Risks and Triggers

There’s no single cause for all cases. Instead, think of RPF as a “final common pathway” where inflammation and immune activation lead to fibrous tissue growth in the retroperitoneum.

Idiopathic (immune-mediated) RPF

Idiopathic RPF is thought to be immune-driven in many cases. In this category, the most talked-about relationship is with IgG4-related disease, where immune cells infiltrate tissues and promote fibrosis. Some people with IgG4-RD have disease in other organs as well (such as salivary glands, pancreas, bile ducts, kidneys, or the aorta), while others present primarily with retroperitoneal involvement.

Secondary RPF

Secondary RPF can be associated with:

• Medications: Certain drug classes have been linked to RPF, including some ergot-derived medications and other agents historically associated with fibrotic reactions.
• Malignancy: Some cancers can mimic RPF or trigger fibrotic responses. This is a key reason clinicians sometimes recommend biopsy.
• Infections: Infections (including tuberculosis in some contexts) have been associated in a subset of cases.
• Radiation therapy or prior surgery/trauma in the area.
• Inflammatory/autoimmune conditions: In some people, RPF appears alongside systemic inflammatory diseases.

Risk factors often discussed

• Age: Often diagnosed in middle adulthood (though it can occur at other ages).
• Sex: Many references note higher frequency in men.
• Smoking: Reported as a risk factor in multiple clinical summaries.
• Asbestos exposure: Occupational exposure has been associated with increased risk in some studies.

Not everyone with these risk factors will develop RPF, and many people with RPF have none of them. They’re clues, not destiny.

How RPF Is Diagnosed

Because symptoms can be vague, diagnosis often starts with a routine workup for back pain, abdominal pain, or kidney abnormalities. RPF is usually identified through a mix of imaging, labs, and sometimes biopsy.

1) Imaging (the cornerstone)

CT scan and MRI are commonly used to identify the characteristic soft-tissue “plaque” or mass in the retroperitoneum. Imaging helps clinicians see:

• Whether the ureters are being encased or compressed
• Whether there is hydronephrosis (kidney swelling from backed-up urine)
• How extensive the fibrotic tissue is and whether it involves vessels

Sometimes PET imaging is used in selected cases to assess inflammatory activity and guide treatment decisions, especially when IgG4-related disease is suspected.

2) Blood and urine tests

Labs can’t diagnose RPF by themselves, but they provide important context:

• Kidney function: creatinine, eGFR, BUN
• Inflammatory markers: ESR and CRP may be elevated
• Urinalysis: may help assess kidney involvement or rule out other causes
• IgG4 level: may be checked when IgG4-RD is on the table (normal levels don’t fully rule it out)

3) Biopsy (sometimes)

Clinicians may recommend a biopsy when imaging is atypical, when cancer needs to be excluded, or when the diagnosis is uncertain. The goal is to distinguish benign inflammatory fibrosis from malignancy or other mimics. (Yes, this is the medical version of “Is this a harmless fog… or is it a villain in disguise?”)

Treatment Options for Retroperitoneal Fibrosis

Treatment typically has two priorities:

1. Protect the kidneys by relieving ureteral obstruction if present.
2. Control inflammation to shrink/quiet the disease and reduce recurrence risk.

Step 1: Relieve obstruction (when needed)

If urine flow is blocked or kidneys are threatened, doctors may act quickly using:

• Ureteral stents (often placed via cystoscopy) to keep the ureter open
• Percutaneous nephrostomy (a temporary drainage tube directly from the kidney) in some cases

These measures address the emergencyprotecting kidney functionwhile longer-term medical therapy takes effect.

Step 2: Medical therapy to reduce inflammation and fibrosis

Many treatment plans begin with glucocorticoids (steroids) such as prednisone, typically at higher doses initially, then tapered over months depending on response. Steroids often reduce pain and inflammatory activity and can help shrink the mass.

Because prolonged steroids can cause side effects (mood changes, insomnia, weight gain, bone loss, elevated blood sugar, infection risk), clinicians frequently consider steroid-sparing medications, especially when disease is severe, relapsing, or clearly immune-driven.

Common “steroid-sparing” or additional medications (case-dependent)

• Mycophenolate mofetil
• Azathioprine
• Methotrexate
• Cyclophosphamide (selected severe cases)
• Rituximab (especially in IgG4-related disease or refractory disease)
• Tamoxifen (sometimes used when steroids aren’t suitable; evidence varies)

The exact medication choice depends on suspected cause (idiopathic vs secondary), IgG4-related features, severity, kidney involvement, and the patient’s risk profile.

Step 3: Surgical management (selected cases)

If obstruction is persistent, stents are not tolerated, or the anatomy is complicated, surgery may be considered. A common procedure is ureterolysisfreeing the ureter from surrounding fibrotic tissue, sometimes repositioning it to reduce future entrapment.

Surgery can be highly effective for the mechanical problem (the “squeeze”), but it may not treat the underlying inflammatory driver on its ownso medical therapy and monitoring may still be needed.

Monitoring and Follow-Up: The Part That Actually Keeps You Well

RPF often requires long-term follow-up because relapse can happen, especially if inflammation reactivates or if treatment is stopped too early. Follow-up commonly includes:

• Repeat imaging (CT or MRI) to track mass size and activity
• Kidney labs to monitor creatinine/eGFR
• Inflammatory markers in some cases
• Stent checks if stents are placed (including replacement schedules)

For some people, the disease behaves like a “one-and-done” event. For others, it’s more like a series: treat, taper, monitor, adjust.

Complications to Know (So You Can Avoid Them)

Most complications stem from compression of nearby structures. The big one is ureteral obstruction leading to hydronephrosis and potential kidney damage. Other possible complications include:

• Acute or chronic kidney failure if obstruction is severe or prolonged
• Deep vein thrombosis (DVT) or venous congestion if vessels are compressed
• Severe hypertension in some cases
• Aortic involvement in IgG4-related disease (rarely, aneurysm-related concerns)

When to Seek Urgent Care

If you have known or suspected RPF, seek urgent evaluation for:

• Very low urine output or inability to urinate
• Severe flank pain with nausea/vomiting
• Fever plus urinary symptoms or a stent (possible infection)
• Sudden leg swelling, chest pain, or shortness of breath (possible clot)

Questions to Ask Your Clinician (A.k.a. the “Make This Appointment Count” List)

• Do my imaging findings look more like idiopathic RPF, IgG4-related disease, or a secondary cause?
• Is a biopsy recommended in my case to rule out malignancy or other mimics?
• Do I have hydronephrosis or ureteral obstructionand do I need a stent or nephrostomy now?
• What’s the plan for steroid dosing and tapering? What side effects should I watch for?
• Should we add a steroid-sparing medication?
• How often will we repeat imaging and kidney labs?
• What symptoms would mean I should call you immediately?

Real-World Experiences: What Living With RPF Often Feels Like (About )

Because retroperitoneal fibrosis is rare and often sneaky, many people describe a “long runway” before diagnosis. A common story starts with persistent back or flank pain that doesn’t quite behave like a pulled muscle. It may come and go, shift sides, or linger as a dull ache. Some people try new chairs, new mattresses, and new stretching routinesbecause honestly, that’s the most reasonable explanation at first.

Then there’s the fatigue. People often report feeling tired in a way that sleep doesn’t fix. It’s not always dramatic; it can be subtlelike your body is running a few apps in the background you didn’t authorize. When routine bloodwork finally gets done (sometimes for something unrelated), a clinician may notice kidney function changes. That “small lab abnormality” is frequently the moment the investigation accelerates.

For those who develop ureteral obstruction, the experience can become more intense: increased flank discomfort, nausea, or a sense that something is “off” in the abdomen. When imaging reveals hydronephrosis and the fibrotic mass, people often describe two emotions at once: relief (“Finally, a real answer”) and worry (“Wait, scar tissue is squeezing what now?”). If a stent is placed, the immediate relief can be hugekidney numbers stabilize, pressure symptoms improvebut stents can also come with their own day-to-day annoyances, like urinary urgency, discomfort, or the mental load of remembering replacement schedules.

Medical therapy is its own chapter. Many patients say steroids work fast for pain and inflammationsometimes within days or a couple of weeksbut the side effects can feel like an uninvited guest who rearranges your pantry. Sleep changes, mood swings, appetite shifts, and puffy “steroid face” are frequently mentioned. This is why conversations about tapering plans and steroid-sparing options matter: patients often want a strategy that treats the disease and preserves quality of life.

Another common theme is the monitoring cadence. Living with RPF can mean a rhythm of scans, labs, and check-ins. Some people find that structure reassuringproof that someone is watching the kidneys like a hawk. Others find it stressful, especially when scan day approaches. It helps when the care team explains what “improvement” looks like (symptoms, kidney function, imaging changes) and what signs could indicate relapse.

Finally, people often emphasize the value of a coordinated teamtypically involving urology, nephrology, rheumatology, and sometimes vascular or radiology specialists. When communication is good, the experience shifts from “mysterious and scary” to “manageable and mapped out.” And for a condition that can start as a vague ache, having a clear plan can be surprisingly powerful medicine.

Conclusion

Retroperitoneal fibrosis is rare, but it’s not hopelessand it’s definitely not something you should “walk off” forever. The hallmark issue is compression: especially of the ureters, which can silently threaten kidney function. Diagnosis usually relies on imaging, and treatment often combines relieving obstruction (when present) with immune-suppressing medical therapy to calm inflammation and reduce recurrence. If you’re dealing with persistent flank/back pain, unexplained kidney lab changes, or symptoms that don’t add up, RPF is one of the conditions worth ruling outbecause catching it early can make a big difference.