Retroperitoneal Fibrosis: A Puzzle of Elusive Causal Link

Retroperitoneal fibrosis (RPF) is a rare condition characterized by the presence of fibro-inflammatory tissue surrounding the abdominal aorta and iliac arteries, often leading to the involvement of adjacent organs such as the ureters and inferior vena cava. We present a case report of a 56-year-old Caucasian woman with a complex medical history, including Hodgkin's lymphoma treated with chemotherapy and radiotherapy (31 years before), a significant smoking history, and a current presentation of acute kidney injury with oliguria, edema, and hypertension. Initial diagnostic considerations included rapidly progressive glomerulonephritis, supported by clinical and imaging findings. However, the absence of specific autoantibodies and the presence of bilateral calyx-pelvic dilation raised questions regarding alternative diagnoses. Imaging studies, including CT, contrast-enhanced CT, and subsequent MRI, revealed periaortic and paracaval adipose tissue thickening suggestive of periaortitis, leading to a diagnosis of retroperitoneal fibrosis. The multifactorial etiology, including previous radiation therapy, lymphoma history, and significant smoking, posed challenges in establishing a definitive causal link. Despite extensive investigations, including laboratory tests and imaging modalities, no single etiological factor could be conclusively identified. This case underscores the diagnostic complexity of RPF, especially in the presence of multiple potential risk factors, and highlights the importance of considering this condition in the differential diagnosis of patients presenting with renal dysfunction and obstructive uropathy.

Serum IgG4 Concentration Is a Potential Predictive Biomarker in Glucocorticoid Treatment for Idiopathic Retroperitoneal Fibrosis

Objectives: To evaluate the management and outcome of idiopathic retroperitoneal fibrosis (iRPF) in Japan, and to identify its clinical biomarker. Methods: We retrospectively analyzed 129 patients with iRPF treated between January 2008 and May 2018 at 12 university and related hospitals. Patients treated with glucocorticoid were analyzed to identify a predictive biomarker. These patients were classified into three groups according to overall effectiveness (no change: NC, complete response: CR, and partial response groups: PR), and each parameter was compared statistically. Results: Male–female ratio was 5:1, and median age at diagnosis was 69 (33–86) years. Smoking history was reported in 59.6% of the patients. As treatment, 95 patients received glucocorticoid therapy with an overall response rate of 84%. As a result, serum concentration of IgG4 was significantly decreased in NC group compared with the other two groups (56.6 mg/dL vs. 255 mg/dL, 206 mg/dL, p = 0.0059 and 0.0078). ROC analysis was performed between the nonresponder (NC) and responder groups (CR + PR) to identify the cut-off value of serum IgG4 as a predictive marker. As a result, AUC of 0.793 was confirmed. Conclusions: Pre-treatment serum IgG4 concentration may have potential as a predictive biomarker of steroid treatment.

Differences of clinicopathological features between IgG4-related and non-IgG4-related idiopathic retroperitoneal fibrosis

OBJECTIVE

To evaluate the clinical and pathological features of IgG4-related and non-IgG4-related idiopathic retroperitoneal fibrosis (IRF) according to the latest classification criteria for IgG4-related disease in 2019.

METHODS

Patients with IRF confirmed by histological examination from our hospital between 2000 and 2020 were selected in this study. Medical records of all patients were reviewed by independent researchers. Retroperitoneal specimens were obtained for hematoxylin & eosin staining, elastic-collagenous fiber staining, and immunohistochemical analysis. The clinical and pathological features between IgG4-related and non-IgG4-related IRF were analyzed.

RESULTS

A total of 105 patients were included with 77 in the IgG4-related group and 28 in non-IgG4-related group. The ratio of male to female patients and the incidence of acute renal failure were significantly higher in the IgG4-related group than in the non-IgG4-related group. Elevated erythrocyte sedimentation rate and C-reactive protein were more common and the recurrence rate was significantly higher in the IgG4-related group than in the non-IgG4-related group. Radiographically, the ureter was more easily involved by retroperitoneal soft tissue in the IgG4-related group. Histologically, there were no significant differences in the incidence of dense lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis between the two groups except for the IgG4 staining.

CONCLUSIONS

Idiopathic retroperitoneal fibrosis can be classified into IgG4-related and non-IgG4-related subtypes. There were no significant pathological differences between the two subtypes of IRF, except for the IgG4 staining. Patients with the IgG4 subtype tended to be more likely to be male, have a higher inflammatory index, and be more likely to have recurrence.

Atypical Presentation of Idiopathic Retroperitoneal Fibrosis Effectively Treated With Colchicine After Lymphoma Misdiagnosis

Idiopathic retroperitoneal fibrosis (RPF) is a rare disease characterized by a fibro-inflammatory mass encasing the abdominal aorta. We report a case of a 43-year-old man with an unusual presentation of RPF who was initially misdiagnosed with lymphoma. Our patient presented with constipation and did not have common findings such as ureteral displacement or renal impairment. Our patient had a complicated disease course complicated by multiple treatment failures and pulmonary embolism. We discuss the patient's first 100 months of treatment, which included the use of prednisone, mycophenolate, tamoxifen, methotrexate, azathioprine, and, now, colchicine. Our case demonstrates that physicians should maintain an index of suspicion for RPF in patients with a homogenously attenuated mass encasing the anterior aorta. It also serves as one example in which RPF appeared to be responsive to colchicine.

Characteristics of Adult Patients with Idiopathic Retroperitoneal Fibrosis and Assessment of Risk of Relapse at Diagnosis

OBJECTIVES

To compare adult patients' characteristics suffering from idiopathic retroperitoneal fibrosis between "relapse-free" and relapsing patients at the diagnosis and identify factors associated with relapse at initial presentation.

METHODS

We conducted a retrospective multicentric study in four hospitals in Eastern France, from 1993 to 2020, of adult patients suffering from idiopathic retroperitoneal fibrosis. We analyzed clinical, biological, and radiological features at diagnosis and during a forty-month follow-up.

RESULTS

Of 47 patients suffering from retroperitoneal fibrosis, 21 patients had idiopathic retroperitoneal fibrosis. Among them, 13 experienced one or more relapses during follow-up. At diagnosis, clinical characteristics, relevant comorbidities, biological and radiological features were similar between groups. Smoking cessation seems associated with decreased relapse risk (p: 0.0624). A total of 8 patients developed chronic renal failure during follow-up. Ureteral infiltration at diagnosis was associated with evolution to chronic renal failure (p: 0.0091).

CONCLUSION

No clinical, biological, or radiological features could predict relapse at retroperitoneal fibrosis diagnosis, but smoking cessation may prevent relapse.

Idiopathic retroperitoneal fibrosis: an update for nephrologists

Idiopathic retroperitoneal fibrosis (IRF) is a rare condition characterized by the development of a peri-aortic and peri-iliac tissue showing chronic inflammatory infiltrates and pronounced fibrosis. Ureteral entrapment with consequent obstructive uropathy is one of the most common complications of IRF, which can lead to acute renal failure and, in the long term, to varying degrees of chronic kidney disease. IRF may be isolated or develop in association with autoimmune diseases (e.g. Hashimoto's thyroiditis and psoriasis) and other fibro-inflammatory disorders (often within the spectrum of immunoglobulin G4-related disease), which suggests that it should be considered as a potentially systemic condition. IRF is an immune-mediated disease: genetic variants (e.g. human leukocyte antigen (HLA)-DRB1*03) and environmental agents (mainly exposure to asbestos and smoking) are strongly associated with an increased risk of developing the disease, while a complex network of chemokines (e.g. CXCL12 and C-C moti chemokine 11 (CCL11)) and cytokines [e.g. interleukin (IL)-6, IL-12 and IL-13] is likely to orchestrate the inflammatory response and simultaneously promote fibrosis. Glucocorticoids, alone or in combination with traditional immunosuppressants such as methotrexate and mycophenolate mofetil, are usually efficacious and promptly induce disease remission; however, up to 50% of patients relapse, thus requiring repeat immunosuppressive courses. Biologic drugs, namely rituximab, are being explored for the treatment of IRF. In addition to medical therapies, interventional procedures (mainly ureteral stenting) are required to relieve ureteral obstruction, whereas surgical ureterolysis is generally reserved to refractory cases. If appropriately treated, then the overall and renal prognosis of IRF are good, with <5% patients developing end-stage renal disease.

Idiopathic Retroperitoneal Fibrosis Presenting as Low Back Pain

Retroperitoneal fibrosis is a rare condition characterized by the presence of fibrous inflammatory tissue in the retroperitoneal structures, such as the infrarenal great vessels and ureters. We are reporting an atypical case of an alcoholic who presented with chronic back pain and abnormal liver function tests. Abdominal imaging revealed an incidental, ill-defined, abnormal soft tissue mass in the left pelvis and mild to moderate left hydroureteronephrosis. Interventional radiology (IR)-guided core biopsy reported cores of dense fibrous tissue with extensive lymphoplasmacytic infiltrates, consistent with idiopathic retroperitoneal fibrosis (IRF). The patient had a left ureteral stent placed and, subsequently, had robotic surgery for ureteral reimplantation.

Idiopathic retroperitoneal fibrosis causing unilateral ureteral and sigmoid colon obstruction: A case report

OBJECTIVE

The present report aimed to present a unique case of idiopathic retroperitoneal fibrosis (RPF) presenting features of unilateral ureteral and sigmoid colon obstruction. RPF is a rare disorder with unclear etiology.

CASE REPORT

A 43-year-old female had a 10-day history of lower right abdominal and lumbar pain. Gynecological examination, ultrasound, and computed tomography (CT) were all suggestive of right ovarian tumor. An enhanced CT showed right-sided hydronephrosis. The patient was diagnosed as having ovarian cancer. Ten days after hospitalization, a right intraureteral stent with a double-J catheter was inserted. Upon exploring the abdomen, unyielding RPF was encountered. A partial sigmoidectomy and colostomy were performed. Postoperative pathological results suggested idiopathic RPF. She received steroid treatments.

CONCLUSION

RPF is a rare disease that can be misdiagnosed. Our understanding about its presentation has to be improved and it should be considered as a differential diagnosis for patients presenting with abdominal diseases.

Management of idiopathic retroperitoneal fibrosis from the urologist's perspective

INTRODUCTION

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterized by a fibrotic reaction that affects retroperitoneal organs, especially the urinary tract. In this review we analyze the current imaging techniques, morphological characteristics, clinical aspects and therapeutic aspects of idiopathic retroperitoneal disease.

METHODS

A PubMed search was conducted in December 2013 to find original articles, bibliographic reviews and series reports published in the past 15 years on idiopathic retroperitoneal fibrosis, its management and outcomes by combining terms like retroperitoneal fibrosis, periaortitis, treatment and autoimmune. A total of 89 articles were included in this review that referred strictly to IRF. We analyzed the imaging tools used for diagnostic and the decision making protocol used by physicians in the management of IRF.

RESULTS

A computerized tomography (CT) scan represents the most commonly used imaging technique for diagnosis. Magnetic resonance imaging (MRI) is unable to differentiate more accurately between benign and malignant retroperitoneal fibrosis (RF) than a CT scan. Biopsy remains the most reliable diagnostic tool for IRF. However, the histological characteristics of IRF are not yet well-defined and the protocol for biopsy is not standardized in terms of template, number of biopsies and the immunohistochemical panel needed for positive diagnosis. The most common treatment reported is corticosteroid therapy alone or in combination with other immunosuppressants, whereas surgical treatment is reserved for severe cases. Indwelling ureteric stents represent the most common procedure for renal drainage, but their efficacy is questionable. Open ureterolysis remains the gold standard for surgical treatment, but its purpose is only to resolve the ureteric obstruction, not to treat the retroperitoneal fibrosis. Laparoscopic and robotic approaches have been reported to be feasible, but no prospective, comparative trials have been performed due to the rarity of the disease. Surgical technique is not standardized and the outcome of the treatment only evaluates the recovery of the renal function.

CONCLUSIONS

The imaging procedures available today are unable to accurately differentiate between idiopathic and malignant RF. A biopsy is mandatory to confirm the diagnosis, but there is no consensus regarding the template, timing and number of biopsies needed to exclude malignancy. Open ureterolysis represents the main surgical treatment for cases with severe IRF, and laparoscopic or robotic approach may be an option in selected cases. The recovery of the renal function is a surrogate for evaluating the success of the treatment. More clinical studies are needed in order standardize the protocol for diagnostic, treatment and follow up after medical or surgical management.

Retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a rare disease that is marked by systemic inflammation and the development of a periaortic fibroinflammatory mass. The fibroinflammatory infiltration can encase the abdominal aorta, ureters, and other abdominal organs. The clinical presentation often includes constitutional symptoms, abdominal pain, and signs of renal insufficiency or renal failure related to ureteral obstruction. Less frequently, RPF may present with vascular complications, such as venous thrombosis or claudication. The idiopathic form of RPF is most common but secondary forms have been described and are associated with malignancy and a variety of different medications. The pathophysiology is uncertain, but RPF has been linked with periaortitis and IgG4-related disease. Treatment centers on the relief of symptoms and complications associated with mass effects. Corticosteroids and other immunosuppressant therapies can improve constitutional symptoms, reduce infiltrate mass, and achieve disease remission, but a chronic relapsing course is not uncommon.

18F-FDG Positron Emission Tomography/Computed Tomography in the Diagnosis and Post-Therapeutic Treatment in a Patient with an Early Stage of Retroperitoneal Fibrosis

Here, we report an experience about 18F-FDG-PET/CT in a patient with an early stage of Idiopathic Retroperitoneal Fibrosis (IRF). At the diagnosis Contrast Enhanced Computed Tomography (CE-CT) revealed periaortic solid tissue in the infrarenal section and locoregional lymph nodes; findings were interpreted as lymphomatous tissue. 18F-FDG-PET/CT showed elevated 18F-FDG uptake in the periaortic tissue but no uptake was detected in lymph nodes. The histologic examination showed recent-onset IRF. The patient began corticosteroid therapy. Nearly at the end of the therapy, CE-CT showed the enlargement of the fibrous tissue and 18F-FDG-PET/CT showed an increased 18F-FDG uptake in the aforesaid lesion and another area of uptake in the aortic wall. 18F-FDG-PET/CT can play an important role in the diagnosis of patients with an initial clinical suspicion of retroperitoneal fibrosis and in their management. Then the patient began a therapy with methotrexate and after six months we performed an 18F-FDG-PET/CT which didn’t show 18F-FDG uptake.

Conflict of interest:None declared.

Prognostic factors in retroperitoneal fibrosis

The aim of this study is to evaluate effective prognostic factors in the evolution of patients with retroperitoneal fibrosis and to establish the validity of fractal analysis in determining the disease severity in these patients.

MATERIAL AND METHODS

This study included 19 patients (M/F: 5/14) treated for idiopathic retroperitoneal fibrosis and bilateral obstructive renal failure between Jan 2004-Dec 2008. Patients were identified retrospectively, searching for patients diagnosed with IRF, after retroperitoneal biopsy or, in most cases the diagnosis rested on radiological findings, especially CT, with identification of a retroperitoneal mass, the absence of other demonstrable renal or ureteric disease or any other pathology that could explain the findings. CT was very useful in describing the retroperitoneal mass around the aorta and inferior vena cava, the extent of the lesion and for monitoring the response to surgical treatment during the follow-up. The data were evaluated about medical history, physical examination findings, laboratory tests (serum urea and creatinine, blood sugar, sodium, potassium, bicarbonate levels, serum pH, uric acid, haematocrit, white blood cell count), imaging methods (renal ultrasound, abdominal CT-scan, MRI). At admission all patients had active disease with obstructive renal failure and underwent bilateral ureteric stenting in order to normalize the BUN levels. After normalizing of BUN levels, ureterolysis and omental wrapping was performed. Postoperatively, ureteric stents were removed after 1 month and remission of renal disfunction was obtained in approximately 5 months (range 2-10 months). All patients were followed for at least 1 year. Patients were regularly checked every 3 months.

RESULTS

Of the 19 patients, there were 5 men and 14 women. The median age at diagnosis of RF was 50 years (range 42-64 years). The most frequent presenting symptoms were back or abdominal pain, weakness, weight loss, oligoanuria, arterial hypertension and mild fever. The duration of symptoms before diagnosis ranged from 6 to 18 months. At presentation all patients had active disease, presenting renal dysfunction with a median serum creatinine of 5.18 mg/dl (range 1-15.4 mg/dl). Most of the patients had moderate bilateral hydronephrosis (2nd degree hydronephrosis). In our study, all patients had excellent prognosis, with full recovery of renal function in 78% of cases (15 patients). The fractal dimension of the fibrosis mass contour correlates with level of renal function impairment. Even more, the fractal dimension seems to slightly variate between CT evaluations (1.30 +/- 0.1), suggesting a non aggressive pattern of extension of the fibrotic mass characteristic for benign lesions.

CONCLUSIONS

The imaging parameters did not predict the disease severity, except the increase in fractal dimension of fibrosis surface area. Efficacy of bilateral ureteric stenting in improving renal function is limited in most of the cases. Dispite the level of renal function impairment at admission, full recovery can be achieved after bilateral ureteric stenting/nephrostomy and ureterolisis.

Idiopathic retroperitoneal fibrosis associated with Hashimoto's thyroiditis in an old-aged man

Idiopathic retroperitoneal fibrosis (IRPF) is a rare disease characterized by a retroperitoneal inflammatory proliferative fibrosing process. Hashimoto's thyroiditis is the most common inflammatory condition of the thyroid gland; and is a frequently-occurring autoimmune disorder manifesting predominantly in middle-aged women. We report a rare association of IRPF with Hashimoto's thyroiditis in a 67-year-old man demonstrating good response to steroid therapy.

Isolated periaortitis: clinical and imaging characteristics

Chronic periaortitis includes a variety of conditions that have similar clinical and histopathological findings, and thus probably represents different manifestations of the same disease: idiopathic retroperitoneal fibrosis, perianeurysmal retroperitoneal fibrosis, and inflammatory abdominal aortic aneurysms. We describe the clinical and imaging characteristics of the nonaneurysmal form of chronic periaortitis, recognized as isolated periaortitis, in an adult male patient presented with low back pain.

Idiopathic retroperitoneal fibrosis presented as an abdominal mass and nephrotic syndrome

We present a 30-year-old male patient who was initially diagnosed as minimal change nephrotic syndrome, 5 years later, the patient developed a localized form of idiopathic retroperitoneal fibrosis (IRF). An elevated ESR and concomitant nephrotic syndrome in the patient suggested the immunologic nature of IRF, IRF has been reported in association with collagen diseases and rarely with proliferative and nonproliferative glomerulopathies. To our knowledge, the association between minimal change lesion (MC) and IRF has not been reported. Furthermore, the fact that IRF presented itself as an abdominal mass and lacked systemic symptoms was also unusual.