Xanthogranulomatous pyelonephritis in adults: clinical and radiological findings in diffuse and focal forms

Fatal nephrobronchial fistula arising from xanthogranulomatous pyelonephritis: a case report

Introduction

Nephrobronchial fistula is an exceptionally rare complication of renal infections, including the uncommon xanthogranulomatous pyelonephritis. Existing literature is limited to a few case reports, with antibiotic therapy and nephrectomy being the preferred treatments.

Case

We present the case of a 63-year-old woman with a history of recurrent xanthogranulomatous pyelonephritis in her right kidney, requiring drainage through lumbotomy. She presented with a chronic dry cough and weight loss, without other noticeable symptoms. Imaging suggested a pulmonary abscess and nephrobronchial fistula. Despite antibiotic treatment and surgical intervention, her condition progressed fatally.

Conclusion

Nephrobronchial fistulas are extremely complications of renal infections, often presenting with nonspecific symptoms. This case highlights their significant impact on morbidity and mortality, especially in resource-limited settings, and underscoring the urgent need for prompt diagnosis and treatment.

Xanthogranulomatous pyelonephritis in a patient with polycystic kidney disease without underlying risk factors: a case report

Xanthogranulomatous pyelonephritis (XGP) is an extremely rare, chronic granulomatous inflammatory condition thought to arise secondary to a combination of obstruction, recurrent bacterial infection and an incomplete immune response although the etiology of XGP is more complex. We would like to report a case of XGP occurring in a patient with polycystic kidney disease (PCKD), which has not been previously documented in etiology. A 29-year-old woman presented to our hospital with right upper quadrant pain for 5 days. She had experienced a low-grade fever, generalized weakness, and myalgia throughout her body for 2 weeks. She had no history of renal stones or recurrent UTIs. Contrast-enhanced CT revealed a well-enhancing large septated cystic mass in the right kidney and numerous cysts in the liver and both kidneys. Open right radical nephrectomy was performed due to the suspicion of renal cell carcinoma, as there was no response to antibiotics over 7 days. Gross specimen demonstrated architectural distortion due to xanthomatous nodules and a dilated pelvico-calyceal system filled with pus and blood. Microscopic examination revealed infiltration of neutrophils and lipid-laden macrophages. The patient is currently being followed up in the outpatient clinic without recurrence of XGP. This is the first reported case of XGP in a patient with underlying PCKD. Physicians should consider PCKD as a potential underlying cause of XGP.

Imaging and Clinical Findings of Xanthogranulomatous Inflammatory Disease of Various Abdominal and Pelvic Organs: A Pictorial Essay

Xanthogranulomatous (XG) inflammatory disease is a rare benign disease involving various organs, including the gallbladder, bile duct, pancreas, spleen, stomach, small bowel, colon, appendix, kidney, adrenal gland, urachus, urinary bladder, retroperitoneum, and female genital organs. The imaging features of XG inflammatory disease are nonspecific, usually presenting as a heterogeneous solid or cystic mass. The disease may also extend to adjacent structures. Due to its aggressive nature, it is occasionally misdiagnosed as a malignant neoplasm. Herein, we review the radiological features and clinical manifestations of XG inflammatory diseases in various organs of the abdomen and pelvis.

Xanthogranulomatous pyelonephritis: a systematic review of treatment and mortality in more than 1000 cases

OBJECTIVES

To systematically review the current demographics, treatment and mortality rate associated with xanthogranulomatous pyelonephritis (XGP) and to test the hypothesis that the weighted pooled peri-operative mortality rate will be <10%.

METHODS

Searches were performed of the Cochrane, Embase and Medline databases and the grey literature for studies published during the period 1 January 2000 to 30 August 2021. Eligible studies reported cohorts of ≥10 predominantly adult patients with XGP and described either average patient age or mortality rate.

RESULTS

In total, 40 eligible studies were identified, representing 1139 patients with XGP. There were 18 deaths, with a weighted pooled peri-operative mortality rate of 1436 per 100 000 patients. The mean age was 49 years, 70% of patients were female and 28% had diabetes mellitus. The left kidney was more commonly affected (60%). Four patients had bilateral XGP, and all of whom survived. Renal or ureteric stones were present in 69% of patients, including 48% with staghorn calculi. Urine culture was positive in 59% of cases. Fistulae were present in 8%. Correct preoperative diagnosis occurred in only 45% of patients. Standard treatment continues to comprise a short cause of antibiotics and open radical (total) nephrectomy. Preoperative decompression occurred in 56% of patients. When considered at all, laparoscopic nephrectomy was performed in 34% of patients. Partial nephrectomy was conducted in 2% of patients.

CONCLUSIONS

Xanthogranulomatous pyelonephritis has a lower mortality rate than historically reported. A typical patient is a woman in her fifth or sixth decade of life with urolithiasis. While open radical nephrectomy remains the most common treatment method, laparoscopic, and to a lesser degree partial nephrectomy, are feasible in well selected patients.

Xanthogranulomatous pyelonephritis - A diagnostic and therapeutic dilemma

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of chronic pyelonephritis, occurring in the setting of obstructive uropathy and recurrent urinary tract infections (UTIs). It is difficult to diagnose as it can be asymptomatic until late-stage disease. Localized symptoms such as flank pain and dysuria may be attributed to nephrolithiasis or UTIs without prompting need for further workup. Extrarenal manifestations, most notably fistula formation, may present distal to the kidney and not be readily attributed to a renal pathology. The only known definitive therapy is nephrectomy. A delay in diagnosis can lead to fulminant complications or a more technically difficult nephrectomy. We present three cases of XGP, which serve to highlight the possibility of earlier diagnosis and resultant management options, including the potential for nephron-saving strategies. Early clinical and radiologic suspicion through awareness of risk factors may play an important role in preventing disease progression, avoiding late-stage complications, and improving treatment outcomes.

Xanthogranulomatous pyelonephritis: a review and meta-analysis with a focus on management

PURPOSE

Xanthogranulomatous pyelonephritis (XGP) is a rare form of pyelonephritis more commonly seen in females and diabetics. Frequently associated with renal tract calculi, it is often difficult to diagnose, as it can clinically and radiologically mimic other disorders. Most cases are treated with antibiotics and nephrectomy. The aim of our review is to summarise and analyse the current evidence focusing on management.

METHODS

A literature search was conducted to identify papers relating to xanthogranulomatous pyelonephritis in adults. Studies containing ten or more patients with XGP were included for descriptive analysis, and a meta-analyses of cohort studies conducted comparing open and minimally invasive nephrectomy undertaken. Other papers were included for narrative review.

RESULTS

52 studies were identified, 20 were included for narrative review and 32 retrospective observational studies containing 868 patients were included for descriptive analysis. 99.8% of patients underwent nephrectomy, about one-third laparoscopically. The most commonly cultured organisms were Escherichia coli and Proteus mirabilis. 60% of patients, where reported, underwent preoperative drainage. Seven studies containing 211 patients were included for meta-analysis which found that postoperative complications, length of stay and transfusion requirements were all significantly reduced in those who underwent minimally invasive surgery.

CONCLUSION

The mainstay management of XGP is antibiotic therapy and nephrectomy. Some studies highlight a role for preoperative upper urinary tract drainage, but evidence supporting this is limited. We present the first meta-analyses examining operative approach for patients undergoing nephrectomy for XGP. Though limited by the data available, our meta-analysis indicates minimally invasive nephrectomy for XGP provides better postoperative outcomes.

Focal xanthogranulomatous inflammation of the kidney cyst without pyelitis: a rare presentation mimicking kidney cancer

Xanthogranulomatous pyelonephritis (XGP) is one of the most common granulomatous diseases of the kidney. XGP is subdivided into diffuse, segmental, and focal subtypes. Preoperative diagnosis of focal XGP on radiological imaging can be challenging, especially without involvement of the renal pelvis. Here, we report the case of a 61 year-old male with focal xanthogranulomatous inflammation of the kidney without pyelitis. The lesion presented as a mural nodule on the left renal cortical cyst, and kidney cancer was suspected on the preoperative image. The patient underwent a successful partial nephrectomy. Pathological examination revealed that the mural nodule displayed xanthogranulomatous inflammation and was clearly distinct from the renal pelvis. Thus, it should be considered that a mural nodule in a renal cortical cyst could be xanthogranulomatous inflammation.

Infliximab-Associated Xanthogranulomatous Pyelonephritis: A Rare Complication

Xanthogranulomatous pyelonephritis (XGP) is one of the rare diseases characterized by chronic inflammation and destruction of the renal parenchyma, and it is usually associated with renal infection, and nephrolithiasis. Infliximab is an anti-tumor necrosis factor-alpha (anti-TNF-α) monoclonal antibody, which is widely used for treating inflammatory bowel disease, and it is known to increase the risk of rare and opportunistic infections. In this study, we report a case of XGP presenting after the initiation of infliximab treatment. We highlight one of the possible complications associated with immunosuppression due to infliximab. Furthermore, the importance of increasing the awareness among physicians for early recognition of this rare complication.

Multimodality imaging review of focal renal lesions

Background

Focal lesions of the kidney comprise a spectrum of entities that can be broadly classified as malignant tumors, benign tumors, and non-neoplastic lesions. Malignant tumors include renal cell carcinoma subtypes, urothelial carcinoma, lymphoma, post-transplant lymphoproliferative disease, metastases to the kidney, and rare malignant lesions. Benign tumors include angiomyolipoma (fat-rich and fat-poor) and oncocytoma. Non-neoplastic lesions include infective, inflammatory, and vascular entities. Anatomical variants can also mimic focal masses.

Main body of the abstract

A range of imaging modalities are available to facilitate characterization; ultrasound (US), contrast-enhanced ultrasound (CEUS), computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET), each with their own strengths and limitations. Renal lesions are being detected with increasing frequency due to escalating imaging volumes. Accurate diagnosis is central to guiding clinical management and determining prognosis. Certain lesions require intervention, whereas others may be managed conservatively or deemed clinically insignificant. Challenging cases often benefit from a multimodality imaging approach combining the morphology, enhancement and metabolic features.

Short conclusion

Knowledge of the relevant clinical details and key imaging features is crucial for accurate characterization and differentiation of renal lesions.

Xanthogranulomatous pyelonephritis due to Aspergillus in a non-diabetic older patient

Xanthogranulomatous pyelonephritis is a rare condition characterised by destructive granulomatous inflammation of renal parenchyma. Primary renal Aspergillosis has been reported in patients with immunocompromised states such as diabetes, retroviral disease, organ transplant recipients, etc. We present a unique case of an older adult in his early 60s, presenting with fever and left flank pain with renal angle tenderness, diagnosed with primary renal aspergillosis with xanthogranulomatous pyelonephritis. These symptoms resolved with a long duration of antifungal (itraconazole) therapy and nephrectomy. The unique features are the development of fungal pyelonephritis in the absence of any immunocompromising conditions and the development of xanthogranulomatous changes with no risk factors.

Xanthogranulomatous Pyelonephritis: A Narrative Review with Current Perspectives on Diagnostic Imaging and Management, Including Interventional Radiology Techniques

Xanthogranulomatous Pyelonephritis (XGP) is a rare, chronic granulomatous inflammatory condition thought to arise secondary to a combination of obstruction, recurrent bacterial infection and an incomplete immune response resulting in focal or diffuse renal destruction. This destruction may be profound with the potential to infiltrate surrounding tissues and viscera. The imaging features of XGP can be ambiguous, mimicking malignancy, tuberculosis (TB) and malakoplakia earning the title of "the great imitator". Computed tomography (CT) is the mainstay of XGP diagnosis and staging, accurately quantifying the stone burden and staging the renal destruction, including the extent of extra-renal spread. Although some cases in children have been successfully treated with antibiotics alone, nephrectomy remains the most common treatment for XGP in adults. The specific management strategy needs to be tailored to individual patients given the potential constellation of renal and extrarenal abnormalities. Although XGP has classically required open nephrectomy, laparoscopic nephrectomy has an increasing role to play arising from the advancement in laparoscopic skills, technique and instruments. Nephron-sparing partial nephrectomy may be considered in the focal form. Interventional radiology techniques most often play a supportive role, eg, in the initial drainage of associated abscesses, but have rarely achieved renal salvage. This narrative review seeks to synthesise the existing literature and summarise the radiological approach and interventional radiology management situated in a clinical context.

Imaging Spectrum of Granulomatous Diseases of the Abdomen and Pelvis

A granuloma is a compact organization of mature macrophages that forms because of persistent antigenic stimulation. At the microscopic level, granulomas can undergo various morphologic changes, ranging from necrosis to fibrosis, which along with other specialized immune cells define the appearance of the granulomatous process. Accordingly, the imaging features of granulomatous diseases vary and can overlap with those of other diseases, such as malignancy, and lead to surgical excisions and biopsy. However, given the heterogeneity of granulomas as a disease group, it is often hard to make a diagnosis on the basis of the histopathologic features of granulomatous diseases alone owing to overlapping microscopic features. Instead, a multidisciplinary approach is often helpful. Radiologists need to be familiar with the salient clinical manifestations and imaging findings of granulomatous diseases to generate an appropriate differential diagnosis. ^©RSNA, 2021.

Xanthogranulomatous pyelonephritis in an eight year old male child: A case report and review of the literature

Introduction and importance

Xanthogranulomatous pyelonephritis is an extremely rare but known form of chronic pyelonephritis resulting from prolonged suppuration of the kidney. Pre-operatively, it may mimic renal tuberculosis or neoplastic lesions including renal cell carcinoma due to its vague clinical presentation, equivocal laboratory and radiological investigations. Due to its rarity and academic interest, herein we report such a rare case we recently encountered in our clinical practice.

Case presentation

An-eight-year old male child patient resented to our hospital with three months history of abdominal distension associated with progressive left flank pain. Preoperative investigations including CT-scan were suggestive of nephroblastoma with differential diagnosis of clear cell sarcoma. Radical nephrectomy was performed and histopathology of the specimen confirmed the diagnosis of Xanthogranulomatous pyelonephritis. The patient fared well postoperatively and he had no symptoms in the subsequent follow up visits.

Clinical discussion

Xanthogranulomatous pyelonephritis is a rare, severe and atypical form of chronic pyelonephritis due to infection (E. coli, Proteus) or stones. The disease may resemble renal cell carcinoma preoperatively. Thus, high index of suspicion is necessary for preoperative diagnosis.

Conclusion

Preoperative diagnosis of Xanthogranulomatous pyelonephritis may be a daunting task related to the rarity of its presentation. Thus, scrupulous histopathological evaluation is essential for the definitive diagnosis. Radical nephrectomy is the mainstay treatment of choice especially in diffuse cases.

•

Extremely rare and severe form of chronic pyelonephritis

•

Resulting from prolonged suppuration of the kidney

•

May mimic cancer due to vague clinical presentation, equivocal lab and imaging tests

•

Confirmatory diagnosis is based on histopathological examination.

•

Nephrectomy remains the treatment of choice in almost all cases.

Xanthogranulomatous pyelonephritis in a pediatric patient

Introduction:

Xanthogranulomatous pyelonephritis consists of a chronic infectious and inflammatory process of the renal parenchyma, a variant of chronic obstructive pyelonephritis. It is more prevalent in middle-aged adults, rare in pediatric patients, with less than 300 cases reported in children worldwide.

Report:

Preschooler, aged 2 years and 11 months, male, with 2 months of abdominal distention, increased temperature and intense pallor, associated with microcytic anemia refractory to the use of ferrous sulfate. 1 week before, he had a bulging in his left flank and a hard palpable mass there. Imaging exams (ultrasound and tomography) revealed an overall enlargement of the left kidney, destruction of the renal parenchyma and intense calyceal dilation, forming the "bear's paw" sign, with a staghorn calculus in the pelvis. He underwent treatment with antibiotic therapy and total nephrectomy, with a specimen sent for pathological examination.

Discussion:

a disease of uncertain incidence in the pediatric age group, xanthogranulomatous pyelonephritis is more prevalent in male children and affects mainly the left kidney, being frequently associated with the presence of stones. Clinically, it has nonspecific symptoms, the most common being abdominal distension and asthenia. Laboratory exams shows microcytic, leukocytosis, thrombocytosis and increased inflammation, pyuria, hematuria and proteinuria, in addition to bacterial growth in urine culture. The diagnosis is anatomopathological, but it can be hinted by contrasted CT scan, with the classical sign of the "bear's paw". Treatment may include nephrectomy and broad-spectrum antibiotic therapy.

Xanthogranulomatous pyelonephritis: a focus on microbiological and antibiotic resistance profiles

BACKGROUND

Xanthogranulomatous pyelonephritis (XGP) is an inflammatory condition of the kidney and its treatment most often involves a combination of antibiotics and nephrectomy. This study aimed to define the clinical features and management of XGP, focusing on microbiological aspects and antibiotic therapy.

METHODS

We performed a retrospective study of 27 cases of XGP diagnosed between January 2001 and January 2020 to analyse their clinical and management characteristics. In addition, a literature review was conducted of XGP case series covering the period from 2000-2020. We searched PubMed for case series through April 2020 without language restrictions. Studies reporting case series of XGP (more than ten cases) were included if they were relevant to this study.

RESULTS

Twenty-seven patients were diagnosed with XGP, and 26 of them were histologically proven to have XGP. A total of 81.5% of the patients were female and the mean age was 59.6 years (SD 19.2). The most frequent symptoms were flank pain (70.4%) and fever (59.3%), while 77.8% of patients had renal stones. Proteus mirabilis was detected in the urine culture in 18.5% of patients, followed by detection of Escherichia coli in 14.8% of patients. The computed tomography (CT) findings included perirenal (29.6%) or pararenal (29.6%) involvement in the majority of patients. Twenty-six patients underwent nephrectomy. Piperacillin/tazobactam and ceftriaxone were the most commonly prescribed antibiotics for treatment. The reported piperacillin/tazobactam and ceftriaxone resistance rates were 14.3% and 16.6%, respectively. Twenty-six case series were included in the literature review, reporting 693 cases in total.

CONCLUSION

We found well-established characteristics of XGP patients among series in terms of previous history, clinical, laboratory and imaging findings, and operative and postoperative outcomes. It is important to know the clinical presentation and potential severity of XGP, as well as the most frequently involved microorganisms and their antibiotic resistance profiles, to select the most appropriate antibiotic therapy.

Infiltrative Renal Malignancies: Imaging Features, Prognostic Implications, and Mimics

Infiltrative renal malignancies are a subset of renal masses that are morphologically characterized by a poorly defined interface with the renal parenchyma. Infiltrative renal malignancies are less common but more aggressive than more typical renal malignancies and carry an overall worse prognosis. Although an infiltrative renal process often represents a malignant neoplasm, infiltrative masses include a wide spectrum of diseases including primary renal cortical, medullary, and pelvic tumors; lymphoproliferative processes; metastases; and various infectious, inflammatory, immune-mediated, and vascular mimics. The imaging features of these masses are often nonspecific, but with the appropriate history, laboratory results, and clinical context, the radiologist can help narrow the diagnosis and guide further treatment. An invited commentary by Lee is available online.Online supplemental material is available for this article. ^©RSNA, 2021.

Wunderlich Syndrome: Wonder What It Is

Wunderlich syndrome (WS) refers to spontaneous renal or perinephric hemorrhage occurring in the absence of known trauma. WS is much less common than hemorrhage occurring after iatrogenic or traumatic conditions. Lenk's triad of acute onset flank pain, flank mass, and hypovolemic shock is a classic presentation of WS but seen in less than a quarter of patients. The majority of patients present only with isolated flank pain and often imaged with an unenhanced CT in the emergency department. The underlying etiology is varied with most cases attributed to neoplasms, vascular disease, cystic renal disease and anticoagulation induced; the etiology is often occult on the initial exam and further evaluation is necessary. Urologists are familiar with this unique entity but radiologists, who are more likely to be the first to diagnose WS, may not be familiar with the imaging work up and management options. In the last decade or so, there has been a conspicuous shift in the approach to WS and thus it will be worthwhile to revisit WS in detail. In our review, we will review the multimodality imaging approach to WS, describe optimal follow up and elaborate on management.

Complicated pyelonephritis associated with chronic renal stone disease

Purpose

This article reviews imaging manifestations of complicated pyelonephritis associated with chronic renal stones disease, in particular xanthogranulomatous pyelonephritis (XGP) and emphysematous pyelonephritis (EPN), as potential mimics of other renal diseases and malignances and provides helpful tips and differentiating features that may alert the radiologist to suspect a diagnosis of infection.

Materials and methods

A retrospective review of the records from 6 adult patients (5 females and 1 male, mean age 72,3 years) with diagnosis of XGP associated with chronic nephrolithiasis and 7 adult patients (6 females and 1 male, mean age 59,3 years) with diagnosis of EPN associated with chronic nephrolithiasis from January 2010 to January 2020 was carried out. Computed tomography urography (CTU) with at least an unenhanced scan, and the parenchymal and excretory phases after contrast medium administration performed at our Teaching Hospital were included. When available images related to conventional radiography, ultrasound (US) and magnetic resonance imaging of the same patients, the comparison with CTU images was carried out.

Conclusion

A possible diagnosis of XGP or EPN must always be taken into account when a pyelonephritis is associated with untreated kidney stones, especially whenever clinical presentation is atypical, current therapy is not effective and imaging shows features of dubious interpretation. Due to their rarity and atypical presentation, a multidisciplinary approach is required and an expert radiologist represents a key figure in the multidisciplinary team as he can help to differentiate between benign and malignant lesions and thus avoid unnecessary radical surgical procedures.

Xanthogranulomatous pyelonephritis: a comparison of open and minimally-invasive surgical approaches

To compare perioperative outcomes between patients undergoing minimally-invasive (MIS) and open surgical approaches for the treatment of Xanthogranulomatous Pyelonephritis (XGP). Between 2007 and 2017 we retrospectively identified 40 patients undergoing nephrectomy at our institution for pathologically confirmed XGP. Patients whose operations were ultimately completed with open technique were analyzed with the open cohort, whereas patients whose operations were completed in entirety using any laparoscopic approach were analyzed with the MIS group. Twenty-three patients were analyzed in the open cohort, compared to seventeen in the MIS group. Three patients in the open cohort were converted intraoperatively from MIS to open approach. Compared to the open group, the MIS group less often had an abscess on preoperative CT (11.8% vs 54.5%; p = 0.006). The MIS group also had lower intraoperative blood loss (100 vs 400 mL; p < 0.001), lower rate of blood transfusion (0% vs 45.5%; p = 0.002), lower postoperative intensive care admission (0% vs 34.8%; p = 0.013), and shorter hospital stay (4 vs 7 days; p = 0.013). However, there was no significant difference in high-grade complications between these groups (5.9% vs 34.8%; p = 0.054). Preoperative CT scan may be an important factor when considering operative approach for treatment of XGP. Patients who are able to undergo MIS approach have less blood loss, shorter hospitalization, and are less likely to require intensive care admission, which may be related to the disease process, the surgical technique, or both.

CT imaging of acute and chronic pyelonephritis: a practical guide for emergency radiologists

Contrast-enhanced CT is not routinely indicated in uncomplicated urinary infections, but it may be necessary in patients with specific risk factors (i.e., diabetes, immunocompromised patients, history of stones, or prior renal surgery) or in patients not responding to antibiotics and in detecting complications of pyelonephritis. CT is the gold standard for imaging assessment of pyelonephritis severity. Imaging appearance of acute pyelonephritis, including focal (i.e., wedge-shaped zones of decreased attenuation or hypodense mass) and diffuse (i.e., global enlargement, poor parenchymal enhancement, lack of excretion of contrast, fat stranding) forms, needs to be differentiated from renal infarction, renal lymphoma, and interstitial nephritis. Chronic pyelonephritis-which appears as focal polar scars with underlying calyceal distortion, global atrophy, and hypertrophy of residual tissue-may mimic at imaging lobar infarcts. This pictorial essay reviews the CT imaging appearance of acute and chronic pyelonephritis, their uncommon subtypes, and their complications, with key features for early diagnosis. Their knowledge is crucial for emergency and abdominal radiologists to avoid misdiagnosis with malignancy and to guide the clinician towards the appropriate medical or surgical treatment.

Imaging Manifestations of Acute and Chronic Renal Infection That Mimics Malignancy: How to Make the Diagnosis Using Computed Tomography and Magnetic Resonance Imaging

PURPOSE

To review the computed tomography and magnetic resonance imaging manifestations of acute and chronic renal infections that may mimic malignancy and to provide useful tips to establish an imaging diagnosis.

CONCLUSION

Acute and chronic bacterial pyelonephritis are usually readily diagnosed clinically and on imaging when the diagnosis is suspected based upon clinical presentation. When unsuspected, focal, extensive or mass-like, acute and chronic bacterial pyelonephritis may mimic infiltrative tumours such as urothelial cell carcinoma (UCC), lymphoma, and metastatic disease. Infection may be suspected when patients are young and otherwise healthy when there is marked associated perinephric changes and in the absence of metastatic adenopathy or disease elsewhere in the abdomen and pelvis. Renal abscesses, from bacterial or atypical microbial agents, can appear as complex cystic renal masses mimicking cystic renal cell carcinoma. Associated inflammatory changes in and around the kidney and local invasion favour infection. Emphysematous pyelonephritis can mimic necrotic or fistulizing tumour; however, infection is more likely and should always be considered first. Xanthogranulomatous pyelonephritis can mimic malignancy when focal or multifocal and in cases without associated renal calculi. Malacoplakia is an inflammatory process that may mimic malignancy and should be considered in patients with chronic infection. Bacillus Calmette-Guerin (BCG)-induced pyelonephritis is rare but can mimic renal malignancy and should be considered in patients presenting with a renal mass when being treated with BCG for urinary bladder UCC.

Clinicopathological Spectrum of Xanthogranulomatous Pyelonephritis

Xanthogranulomatous pyelonephritis (XGP) is an uncommon and distinct type of chronic infective pyelonephritis causing destruction of the kidney, severely affecting the renal function. The perinephric adipose tissue and peritoneum is not uncommonly involved. The study was undertaken to decipher the clinicopathologic spectrum of XGP. Forty cases of XGP were diagnosed on histopathology over a period of 13 years (2005–2017). Relevant clinical details and radiological findings were recorded from the case files. Out of a total of 40 cases, 26 were female and 14 were male with a mean age of 39.5 ± 13.6 years. Flank pain was the most common presenting symptom. All the patients had unilateral disease and underwent nephrectomy for a nonfunctional kidney. Gross examination showed enlarged kidney with replacement of cortico-medullary tissue by yellow nodular areas of fatty tissue and dilatation of the pelvicalyceal system. Thirty-six (90%) cases had nephrolithiasis. Histologically, the characteristic feature was the existence of lipid-laden foamy macrophages. Renal parenchymal involvement was diffuse in majority (31, 77.5%). Two (5.0%) of the patients had coexisting carcinoma in the same kidney. Histopathologic examination gives the definitive diagnosis of XGP which relies on the characteristic morphology. Surgical intervention in the form of nephrectomy is the treatment of choice and offers good treatment outcomes.

Symmetric nephromegaly

We report a lady with bilateral symmetrical xanthogranulomatous pyelonephritis (XPGN) presented with acute kidney injury and sepsis, in which both CT and MRI mimicked an infiltrative disease, except that the infiltration was not very homogenous. Eventually, the pathological diagnosis turned out to be XPGN. Most XPGN were unilateral, and there have been a few publications of bilateral involvement. Moreover, this case lacked typical manifestations, such as renal calculus, contracted renal pelvis, or obstructive nephropathy. This image reminds us that bilateral renal infiltrative disease could not completely exclude the possibility of XPGN, in which the inhomogeneity of the infiltration pattern on CT/MRI may be a clue.

Xantogranulomatous pyeloneprhritis in children

Abstract

Xanthogranulomatous pyelonephritis (XPN) is an unusual and severe form of chronic inflammatory lesion of the kidney, characterised by the destruction of the renal parenchyma and the presence of multinucleated giant cells and lipid-laden macrophages, inflammatory infiltration and intensive renal fibrosis. There are a few cases in the literature which describe the disease in children. The pathomechanism of XPN is poorly understood. Renal obstruction with concomitant urinary tract infection is the most commonly associated pathological finding. The process is typically unilateral and may be focal or diffuse. In both cases, the perirenal infiltration is possible and can be mistaken for common renal neoplasm or inflammatory process. The symptoms are non-specific. Diagnostic imaging techniques with clinical suspicion have enabled XPN to be diagnosed and differentiated from malignancy with a high degree of confidence. Computed tomography (CT) is the mainstay of diagnostic imaging. The definitive diagnosis of XPN is based on pathological assessment after nephrectomy. We review and illustrate the clinical, radiological, surgical and pathological characteristics of XPN in children. All cases shown are surgically and histopathologically proven.

Teaching Points

• XPN can present different clinical manifestations.

• CT is the mainstay of diagnostic imaging in XPN.

• Focal type of XPN should be included in the differential diagnosis of children with a renal mass.

• There are no clear guidelines on the management of XPN.

• Conservative and surgical treatments should be considered for each individual case.

• Histopathological examination confirms the diagnosis and excludes other benign and malign diseases.

Focal Xanthogranulomatous Pyelonephritis with Pulmonary Lesions on the Background of Type Two Diabetes Mellitus

Focal Xanthogranulomatous pyelonephritis is a rare chronic inflammatory condition of kidneys which usually is associated with postrenal obstruction or renal stone leading to chronic bacterial infection and eventually chronic glomerular inflammation. About 90% of cases are of the diffuse type and associated with staghorn renal calculi. The case presented in this paper is of the focal type in a 58-year-old diabetic female. Interestingly she did not have symptoms or laboratory presentation of chronic renal bacterial infection except for elevated ESR. She sought medical attention due to severe pulmonary infection of the background of morbid obesity. Imaging studies revealed several pulmonary lesions and a large mass of the right kidney which was indistinguishable from renal malignancy. After surgical resection of the right kidney, the lesion is pathologically diagnosed to be a focal Xanthogranulomatous pyelonephritis. The pulmonary lesions were spontaneously resolved about three months following right nephrectomy.

Pictorial review: Renal ultrasound

Ultrasound (US) is the first-line imaging modality for evaluating azotemic patients for urinary obstruction and renal size. US is also valuable for distinguishing congenital variants and simple cystic lesions from renal masses. Doppler US is effective in detection of renal calculi and evaluation of vascular pathology. Unfortunately, renal US is limited in distinguishing causes of medical renal disease. The kidneys have a complex internal architecture with a highly variable appearance on US. This article illustrates non-neoplastic renal conditions, including normal and embryological variants, parenchymal, cystic, and vascular diseases. Renal infections, calcifications, and trauma and fluid collections are also discussed, with an emphasis on distinguishing US features and pathophysiology.

Xanthogranulomatous pyelonephritis: a case with rare adhesion to pancreas

Xanthogranulomatous pyelonephritis (XGP) is a rare benign condition with unknown aetiology and chronic infection of kidney. Commonly, most cases are related with urinary tract obstruction, nephrolithiasis, infection, diabetes, and/or immune compromise. XGP is associated with destruction of the renal parenchyma and granulomatous inflammation with foamy lipid-laden macrophages resulting from obstructive uropathy. It closely mimics a malignancy, exhibiting local tissue invasion and destruction. Adjacent organs especially duodenum as well as very rarely pancreas or spleen may be involved. Additionally, XGP is known as notorious for fistulisations, such as pyelocutaneous and ureterocutaneous fistulae, which have been reported as well described. XGP may be indistinguishable from renal cell carcinoma by radiographic and clinic consultation so it must be diagnosed based on the histopathologic examinations. Furthermore, macroscopic appearance of XGP is a mass of yellow tissue with focal haemorrhage besides necrosis and in this regard, it grossly resembles renal cell carcinoma. Here, we report the case of a 32-year-old female, preoperatively diagnosed as malignancy by clinical examination. Our further pathological evaluations revealed very rarely adhesion of XGP to pancreas tissue.

CT Imaging of Emergent Renal Conditions

The kidneys are paired intra-abdominal organs which provide essential functions and maintain homeostasis throughout the human body. Numerous disease processes affect the kidneys and cause acute renal dysfunction or other potentially catastrophic complications. These conditions can be broadly categorized into obstructive, infectious, hemorrhagic, traumatic, and vascular diseases. Imaging plays a vital role in the work-up and diagnosis of acute and emergent renal conditions. Evaluation of emergent renal conditions with a focus on CT imaging is discussed.

Xanthogranulomatous Pyelonephritis with Incomplete Double Ureter

Introduction

Xanthogranulomatous pyelonephritis (XGP) is a type of chronic renal inflammation that usually occurs in immunocompromised middle-aged women with chronic urinary tract infection or ureteral obstruction induced by the formation of ureteral stones. XGP with an incomplete double ureter is extremely rare.

Case Presentation

A 76-year-old woman was referred to our department to undergo further examination for a left renal tumor that was detected by ultrasonography. Dynamic contrast computed tomography (CT) revealed an enhanced tumor in the upper renal parenchyma. Laparoscopic radical nephrectomy was performed based on a preoperative diagnosis of renal cell carcinoma. Histological sections showed the aggregation of foam cells; thus, XGP was diagnosed.

Conclusion

We herein report a rare case of XGP in the upper pole of the kidney, which might have been associated with an incomplete double ureter.

Food strategies of renal atrophy based on Avicenna and conventional medicine

Kidneys have an important role in the body. Any damage to kidney role can damage many organs of the body. Traditional Persian Medicine (TPM) or Iranian traditional medicine (ITM) is an ancient temperamental medicine with many literatures about kidney diseases and Avicenna (980-1025 AD) describes kidney diseases in details. This is a review study by searching of the most important clinical and pharmaceutical TPM textbooks such as The Canon of Medicine by Avicenna and scientific data banks using keywords such as "Hozal-e-Kolye", renal atrophy, tubular atrophy, kidney, chronic kidney disease, and end stage renal disease. This paper found that "Hozal-e-Kolye" in TPM texts is the same tubular atrophy in conventional medicine due to some similar symptoms between them. Lifestyle modification and use of proposed foodstuffs can be considered as a complementary medicine in addition to conventional treatments to manage these patients. TPM scholars prescribed some foodstuffs such as camel milk, sheep's milk and Ficus carica for this disease as a complementary management. This study aimed to explain HK (the same tubular atrophy considering their similar symptoms) and introduce some foodstuffs. It seems using of foodstuffs affecting tubular atrophy based on TPM literatures can has a role as a supplemental method in company with conventional medicine management.

Spectrum of Xanthogranulomatous Processes in the Abdomen and Pelvis: A Pictorial Review of Infectious, Inflammatory, and Proliferative Responses

OBJECTIVE

Xanthogranulomatous (XG) processes are rare inflammatory conditions with the characteristic pathologic feature of lipid-laden macrophages or histiocyte cells. Imaging findings are nonspecific and can simulate aggressive neoplastic processes. XG processes can be caused by infection, inflammation, histolytic process, or an inherited lysosomal disorder. XG infectious processes are mainly seen in cholecystitis and pyelonephritis, but several other organs can also be involved. Histiocytic processes can be divided into Langerhans and non-Langerhans cell histiocytosis. The non-Langerhans cell histiocytosis entities include Erdheim-Chester disease, Rosai-Dorfman disease, juvenile xanthogranuloma, and hemophagocytic lymphohistiocytosis. The inherited lysosomal disorders resulting in XG processes include Nieman-Pick, Gaucher, and other lysosomal storage disorders.

CONCLUSION

Radiologists need to be able to recognize features of xanthogranulomatous processes to help facilitate patient management.

Radiological diagnosis of perinephric pathology: pictorial essay 2015

The perinephric space, shaped as an inverted cone, sits between the anterior and posterior renal fasciae. It can play host to a variety of clinical conditions encountered daily in the reporting schedule for a radiologist. Lesions may be classified and diagnosed based on their imaging characteristics, location and distribution. A broad range of differential diagnoses can be attributed to pathology sitting within this space, often without clinical signs or symptoms. An understanding of commonly encountered conditions affecting the perinephric space, along with characteristic imaging findings, can illustrate and often narrow the likely diagnosis. The aim of this essay is to describe commonly encountered neoplastic and non-neoplastic entities involving the perinephric space and to describe their key imaging characteristics.

TEACHING POINT

• Despite often a bulky disease, perinephric lymphoma does not produce obstruction or stenosis. • In primarily fatty masses, defects within the renal capsule likely represent angiomyolipoma. • Consider paraganglioma if biopsy is planned; biopsy may lead to catecholamine crisis.

Unusual case of nephrocutaneous fistula - Our experience

A rare case of nephrococutaneous fistula due to spontaneous expulsion of renal calculi is described. A 45-year-old man presented with urinary leakage from an ulcer over the left lumbar region for the last 3 months after a history of spontaneous expulsion of stones from this area. Ultrasonography abdomen revealed a small contracted kidney with multiple calculi in the kidney and renal pelvis, sinus tract from the lower pole of the left kidney with a ruptured calyceal calculus in the sinus tract. CT urography revealed a non excreting left kidney with multiple renal calculi, with hyperdense collection in the renal parenchyma extending to the subcutaneous tissue and left lung suggesting a xenthogranulomatous pyelonephritis (XGP). We performed a left-sided simple nephrectomy with excision of the fistulous tract. Histopathological examination revealed XGP. There have been a few case reports of XGP forming nephrocutaneous fistula in the back.

Multimodality imaging of renal inflammatory lesions

Spectrum of acute renal infections includes acute pyelonephritis, renal and perirenal abscesses, pyonephrosis, emphysematous pyelonephritis and emphysematous cystitis. The chronic renal infections that we routinely encounter encompass chronic pyelonephritis, xanthogranulomatous pyelonephritis, and eosinophilic cystitis. Patients with diabetes, malignancy and leukaemia are frequently immunocompromised and more prone to fungal infections viz. angioinvasive aspergillus, candida and mucor. Tuberculosis and parasitic infestation of the kidney is common in tropical countries. Imaging is not routinely indicated in uncomplicated renal infections as clinical findings and laboratory data are generally sufficient for making a diagnosis. However, imaging plays a crucial role under specific situations like immunocompromised patients, treatment non-responders, equivocal clinical diagnosis, congenital anomaly evaluation, transplant imaging and for evaluating extent of disease. We aim to review in this article the varied imaging spectrum of renal inflammatory lesions.

Nephrectomy for Non-neoplastic Kidney Diseases

This review discusses the pathology of non-neoplastic kidney disease that pathologists may encounter as nephrectomy specimens. The spectrum of pediatric disease is emphasized. Histopathologic assessment of non-neoplastic nephrectomy specimens must be interpreted in the clinical context for accurate diagnosis. Although molecular pathology is not the primary focus of this review, the genetics underlying several of these diseases are also touched on.

Analysis of 35 cases of Xanthogranulomatous pyelonephritis

BACKGROUND

To retrospectively determine key demographic and clinical features of 35 patients with Xanthogranulomatous pyelonephritis (XGP) in a New Zealand setting and to compare it with the existing literature.

METHODS

A retrospective review of patients having a confirmed diagnosis of XGP on histopathology examination was performed. Key clinical and demographic features were analysed and compared with the published literature.

RESULTS

XGP was diagnosed in 35 patients over a 12-year (2001-2013) period in Auckland Public Hospital. Ninety-one percent of the patients were female. The population had significantly higher numbers of Maori and Pacific Island patients compared with the general population (74%). Staghorn calculi were the most common cause (51.4%) with obstructing ureteric calculi as the next most common (22.9%) cause. Twenty percent of cases were not thought to be XGP prior to nephrectomy (suspicious renal mass). Thirteen (38%) patients suffered serious complications post-operatively (Clavien 3-5).

CONCLUSION

XGP is a rare chronic inflammatory condition that appears to be overrepresented by Maori and Pacific islanders in our cohort when compared with the overall patient pool. Surgical treatment is associated with significant morbidity but remains the only definitive option. Obesity and other conditions associated with metabolic syndrome may coexist at the time of presentation and may be contributing factors to the development of XGP and poor outcomes associated with it.

Xanthogranulomatous prostatitis: multiparametric MRI appearances

Granulomatous prostatitis is an unusual form of prostatitis, and xanthogranulomatous prostatitis (XGP) is an even rarer granulomatous inflammation. Very few XGP cases have been reported in the literature. The reports concerning MRI features of XGP are even less. The present two cases of XGP in our report have different appearances from previous reports and are accompanied by abscess. We also exhibit the magnetic resonance spectroscopy and dynamic contrast-enhanced MRI characteristics, which have never been reported.

Xanthogranulomatous pyelonephritis: Rare presentation of a rare disease

Xanthogranulomatous pyelonephritis is a rare chronic renal infection of unknown pathogenesis characterized by replacement of renal parenchyma by lipid filled macrophages frequently associated with an enlarged, non-functioning kidney and an obstructing calculus. We report a case of a 45 year old non diabetic female who presented with gradually enlarging renal mass with extensive retroperitoneal involvement and a non-functioning kidney with no evidence of obstructing stone or fat density and simulating malignancy. She was diagnosed as stage III Xanthogranulomatous pyelonephritis and managed with radical nephrectomy with favourable outcome.

Xanthogranulomatous Pyelonephritis: Unusual Clinical Presentation: A Case Report with Literature Review

Xanthogranulomatous pyelonephritis (XGP) is rare and aggressive form of chronic infectious pyelonephritis. No single clinical or radiological feature is diagnostic of XGP. A 75-year-old man with prostatic enlargement presented with difficulty and burning micturition fever, abdominal and flank pain. X-ray, ultrasonography and computed tomography scan diagnosis was right kidney pyonephrosis. Intravenous urography revealed non-excretory right kidney. Right nephrectomy was done. Histological diagnosis of XGP was made. In all patients of prostatic enlargement, renal function must be assessed for the extent of damage. Surgery is the treatment choice in most cases. Pre- and post-operative antibiotics are key factors for successful management and better prognosis.

Complicated urinary tract infections associated with diabetes mellitus: Pathogenesis, diagnosis and management

Diabetes mellitus has a number of long-term effects on the genitourinary system. These effects predispose to bacterial urinary tract infections (UTIs) in the patient with diabetes mellitus. Complicated UTIs are also common and potentially life-threatening conditions. They include emphysematous pyelonephritis, emphysematous pyelitis/cystitis, xanthogranulomatous pyelonephritis, renal/perirenal abscess, and renal papillary necrosis. Improved outcomes of these entities may be achieved by early diagnosis, knowledge of common predisposing factors, appropriate clinical and radiological assessment, and prompt management. Herein we review complicated UTIs associated with diabetes mellitus in terms of pathogenesis, clinical manifestations, radiological features, and current management options.

Acute conditions affecting the perinephric space: imaging anatomy, pathways of disease spread, and differential diagnosis

The perinephric space is an important, central compartment of the retroperitoneum which may host various acute conditions. Imaging evaluation of the perinephric space requires an understanding of its anatomy and the pathways of disease spread to and from other retroperitoneal compartments. Numerous acute conditions can affect the perinephric space and may occur in isolation, extend from nearby retroperitoneal structures, or be part of a systemic condition. Familiarity with the key imaging findings of acute conditions affecting the perinephric space is imperative to facilitate diagnosis and guide treatment. The purpose of this article is to review and illustrate the relevant anatomy, pathways of disease spread, and acute pathology encountered during cross-sectional imaging evaluation of the perinephric space.