Retroperitoneal fibrosis: case series of five patients and review of the literature

Non-dilated obstructive nephropathy

Obstructive nephropathy (ON) is a common and reversible cause of post-renal acute kidney injury (AKI) and may be caused by a variety of conditions. It occurs when both the upper urinary tracts are obstructed, or when one tract is obstructed in patients with a solitary kidney. ON is suspected whenever there is evidence of hydronephrosis at imaging. However, not all patients with obstruction develop hydronephrosis and significant obstruction can be present in the absence of hydronephrosis. This syndrome is called non-dilated obstructive uropathy (NDOU). It accounts for about 5% of cases of urinary obstruction and the diagnosis can be challenging. The current paper provides an overview of the literature aiming to identify the main causes of NDOU and its clinical presentation, in order to clarify when to suspect it among AKI cases. A narrative review was performed due to the overall low quality of the available evidence. Only patients with post-renal AKI and a non-dilated or minimal dilation of the intrarenal collecting system were included. As evidenced by our review, NDOU is most prevalent in the fifth and sixth decades of life and affects mainly the male gender. On hospital admission serum creatinine levels are usually very high. Among the most common clinical presentations are oliguria/anuria, abdominal pain, signs of retention such as oedema or pleural effusion, and nausea/vomiting. About three out of four cases of NDOU are due to an ab-extrinsic compression of the ureters caused by retroperitoneal fibrosis or malignant disease. An effective and minimally invasive urinary diversion is obtained with ureteric stenting or a percutaneous nephrostomy. A correct diagnosis of NDOU may be challenging but it is of paramount importance as it can lead to a prompt management with a potential complete resolution of both obstruction and acute renal failure.

A case of idiopathic retroperitoneal fibrosis presenting as gallbladder carcinoma

Background

Retroperitoneal fibrosis (RPF) is a rare disease with a poor prognosis characterized by systemic inflammation and fibroinflammatory tissue. Idiopathic RPF (IRPF) accounts for approximately two-thirds of RPF cases.

Case presentation

A 56-year-old female patient with abdominal distension was admitted to Changxing Hospital. Laboratory tests revealed mild anemia and elevated CA125, while IgG4 and autoantibodies were within the normal ranges. Computed tomography (CT) revealed a gallbladder-occupying lesion, pancreatic cyst and retroperitoneal mass, which may have contributed to bilateral ureteral compression and hydronephrosis. The initial diagnosis was gallbladder carcinoma with lymph node metastasis. Then, abdominal adhesiolysis, cholecystectomy and partial hepatectomy were performed. Histologically, there were fibrosis and inflammation in the retroperitoneal tissue without any malignant cells in the retroperitoneal or gallbladder tissue. Finally, we confirmed the diagnosis of idiopathic retroperitoneal fibrosis, chronic cholecystitis and pancreatic cyst. The patient recovered well following the CT scan, in which dilatation of the bile duct was reduced, and effusion of the bilateral upper ureter was no longer significant.

Conclusion

This atypical case illustrates that RPF can be combined with other biliary tract diseases. The coexistence of other diseases conceals the symptoms of RPF, which increases the difficulty of image identification. A high degree of suspicion is necessary for routine clinical work. As more cases are reported, further advances in the diagnosis and treatment of RPF can be expected.

Poricoic acid A suppresses TGF-β1-induced renal fibrosis and proliferation via the PDGF-C, Smad3 and MAPK pathways

Renal interstitial fibrosis is the most important pathological process in chronic renal failure. Previous studies have shown that poricoic acid A (PAA), the main chemical constituent on the surface layer of the mushroom Poria cocos, has protective effects against oxidative stress and acute kidney injury. The present study aimed to investigate the potential roles of PAA on the pathological process of renal fibrosis and the associated molecular mechanism. The NRK-49F cell line was treated with transforming growth factor-β1 (TGF-β1) with or without PAA or platelet-derived growth factor C (PDGF-C). Cell Counting Kit-8 assay, western blotting and 5-ethynyl-2'-deoxyuridine immunofluorescence staining were performed to examine cell growth, protein expression and cell proliferation, respectively. Data from the present study showed that 10 µM PAA attenuated TGF-β1-induced NRK-49F cell extracellular matrix (ECM) accumulation, fibrosis formation and proliferation. Renal fibrosis with the activation of Smad3 and mitogen-activated protein kinase (MAPK) pathways were also inhibited by PAA treatment. PDGF-C reversed the inhibitory effects of PAA on TGF-β1-induced renal fibroblast proliferation and activation of the Smad3/MAPK pathway. The present study suggested that suppression of TGF-β1-induced renal fibroblast ECM accumulation, fibrosis formation and proliferation by PAA is mediated via the inhibition of the PDGF-C, Smad3 and MAPK pathways. The present findings not only revealed the potential anti-fibrotic effects of PAA on renal fibroblasts, but also provided a new insight into the prevention of fibrosis formation via regulation of the PDGF-C, Smad3 and MAPK signaling pathways.

Retroperitoneal fibrosis; a single-centre case experience with literature review

Objective

We present 13 patients with retroperitoneal fibrosis, focusing on clinical features, radiological characteristics, treatments and their outcomes.

Methods

Retrospective review of the medical records was performed of all retroperitoneal fibrosis patients diagnosed and treated in our department between 2012 and 2017.

Results

Twelve patients were male, with a median age of 64 years. Eleven patients presented with abdominal pain or back pain or both. Aetiologies varied from idiopathic to malignancy and vasculitis. Twelve patients had PET scans. These showed ¹⁸F-fluorodeoxyglucose-avid retroperitoneal soft tissue around the abdominal aorta in the vast majority, with five scans also demonstrating localized or generalized uptake by the aorta. In all cases except one, glucocorticoids were applied as the first-line therapy. Further immunosuppressive therapy was required in 10 cases.

Conclusion

Our patients were male and older in age compared with the existing literature. PET scans were very helpful in diagnosis of retroperitoneal fibrosis. Rituximab was found to be an effective treatment in six of our patients.

Retroperitoneal fibrosis - a report of five cases

Retroperitoneal fibrosis (RPF) is a rare disease, characterized by inflammation and deposition of fibrotic tissue in the vicinity of the abdominal aorta and iliac arteries. We present a report of five patients admitted to our department between January 2014 and February 2017, diagnosed with RPF. Abdominal pain was the most common presenting symptom; however, in one patient, RPF was identified accidentally in routinely performed ultrasonography. In 4 cases, corticosteroids (CS) in combination with azathioprine were applied as first-line therapy, whereas one patient was treated with intravenous methylprednisolone pulses followed by oral CS. In this paper, clinical features as well as laboratory and radiographic findings together with management and treatment outcomes in patients with RPF are discussed. Given the rarity of the condition, it seems important to report every single case of RPF to help establish its management algorithm.

Retroperitoneal Fibrosis Due to Opium Abuse: A Case Series and Literature Review

Retroperitoneal fibrosis (RPF) is a rare condition with an unclear etiology, presenting with the development of aberrant chronic nonspecific fibroinflammatory tissue in the retroperitoneal space, which can result in entrapment and obstruction of the retroperitoneal structures. RPF is a subtype of chronic periaortitis, and can be divided into two types: primary (or idiopathic) and secondary. RPF is usually idiopathic, but can also be secondary to malignancies, certain drugs, infections, surgery, and trauma. The systemic clinical manifestations are nonspecific and include low-grade fever, fatigue, anorexia, weight loss, and myalgia. We report five patients admitted to our hospital with clinical, laboratory, imaging, and pathologic findings compatible with RPF, and we describe their treatment and follow-up. We were suspicious that the impurities of some types of opium have an important role in the pathogenesis of RPF. Some of our patients used opium again after the follow-up period; however, they used a different type with a different origin, and we were surprised to see that RPF did not form again.

Acute renal vein thrombosis and nephrotic syndrome in the setting of retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (RPF) is a rare disease that involves non-specific inflammation and fibrosis surrounding the aorta. As a result, RPF is a challenging diagnosis to make; patients often seek medical attention after complications arise, such as nephrotic syndrome. The patient in our case report initially complained of flank pain. Laboratory evaluation revealed acute renal failure and nephrotic syndrome with substantial proteinuria. Multiple imaging modalities demonstrated a large, ill-defined, infiltrative retroperitoneal soft tissue mass that encased the great vessels. The patient was also noted to have acute left renal vein thrombosis. Although the patient was eventually diagnosed with RPF of unknown etiology, his clinical course is particularly unique given the rarity of the renal vein thrombosis. This case report adds a value to the medical community by helping to elucidate RPF and exposing its potentially life-threatening complications.