Xanthogranulomatous Pyelonephritis: Case Report.

BACKGROUND: In the emergency department (ED), pyelonephritis is a fairly common diagnosis, especially in patients with unilateral flank pain. Xanthogranulomatous pyelonephritis (XGP) is a rare type of pyelonephritis that is associated with unique features, which may lead to its diagnosis. CASE REPORT: A 30-year-old male patient presented to the ED for evaluation of right-sided abdominal pain that has been ongoing for the past 24 hours. He noted the pain was located predominantly in the right flank and described it as sharp in nature. The pain was nonradiating and was associated with scant hematuria. He stated that he had similar pains approximately 1 month earlier that resolved after a few days. The patient underwent a bedside ultrasound and a subsequent computed tomography (CT) scan of the abdomen and pelvis, which showed an enlarged, multiloculated right kidney with dilated calyces and a large staghorn calculus, findings that represent XGP. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report highlights an unusual variant of pyelonephritis, a relatively common ED diagnosis. XGP should be considered in patients with recurrent pyelonephritis, as treatment for XGP may require surgical intervention in addition to traditional antibiotic management.

Xanthogranulomatous Pyelonephritis in a Neonate Masquerading as Renal Mass.

Xanthogranulomatous pyelonephritis (XGP), a variant of chronic obstructive pyelonephritis, is a very rare diagnosis in neonates with three reported cases to date. It is often misdiagnosed in infancy as it mimics the features of renal mass. Herein, we report a case of 20-day-old neonate with XGP presenting as a renal mass.

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.

Perioperative outcomes and risk factors for major complications associated with nephrectomy for Xanthogranulomatous pyelonephritis: a multicenter study.

PURPOSE: To determine the risk factors associated with major complications in patients with histologically confirmed Xanthogranulomatous pyelonephritis (XGP) who underwent nephrectomy. METHODS: A multicenter retrospective study was performed including patients who underwent nephrectomy between 2018 and 2022 with histopathological diagnosis of XGP. Clinical and laboratory parameters at the initial presentation were evaluated. Data on extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of nephrectomy and perioperative outcomes were obtained. The primary outcome was major complications, defined as a CD ≥ grade 3 and the need for intensive care unit (ICU) admission. Secondary outcomes included the comparison of complications evaluating the nephrectomy approach (transperitoneal, retroperitoneal, and laparoscopic). A sub-analysis stratifying patients who needed ICU admission and Malek classification was performed. RESULTS: A total of 403 patients from 10 centers were included. Major complications were reported in 98 cases (24.3%), and organ injuries were reported in 58 patients (14.4%), being vascular injuries the most frequent (6.2%). Mortality was reported in 5 cases (1.2%). A quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥ 2, increased creatinine, paranephric extension of disease (Malek stage 3), a positive urine culture, and retroperitoneal approach were independent factors associated with major complications. CONCLUSION: Counseling patients on factors associated with higher surgical complications is quintessential when managing this disease. Clinical-radiological staging, such as the Malek classification may predict the risk of major complications in patients with XGP who will undergo nephrectomy. A transperitoneal open approach may be the next best option when laparoscopic approach is not feasible.

Xanthogranulomatous pyelonephritis with polycystic kidney disease as a mimic of cystic renal cell carcinoma: a case report.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is a rare chronic pyelonephritis that often mimics other renal diseases, when combined with autosomal dominant polycystic kidney disease(ADPKD), preoperative diagnosis is exceedingly difficult. It is important for clinicians to be aware of an XGP with ADPKD since a misdiagnosis can lead to unnecessary surgical intervention. CASE PRESENTATION: Here, we report a case of a 66-year-old female with a history of bilateral ADPKD and urinary tract infection admitted to our hospital due to right flank pain, feeble, and low-grade fever. Contrast-enhanced ultrasound revealed a malignant mass of the right kidney suspected to be a cystic renal cell carcinoma with polycystic kidney disease. In addition, contrast-enhanced computed tomography (CT) and fluorine 18 fluorodeoxyglucose PET/CT (18F FDG PET/CT) showed similar results. Subsequently, the patient underwent a right radical nephrectomy, but histopathological examination revealed XGP with ADPKD. On the follow-up, the patient's symptoms were relieved. CONCLUSIONS: XGP should be kept in mind during the differential diagnosis of renal masses with ADPKD even in the absence of characteristic clinical symptoms and imaging manifestations.

Metastatic xanthogranulomatous pyelonephritis managed with immunosuppression.

A male aged in his mid-60s was diagnosed with xanthogranulomatous pyelonephritis after a left nephrectomy for a renal mass that was detected during the investigation of weight loss and drenching night sweats. Past medical history includes type 2 diabetes mellitus, transient ischaemic attack, hypertension, non-alcoholic fatty liver disease, dyslipidaemia, osteoarthritis and active smoking. Three years after the initial diagnosis, the patient represented with abdominal pain. CT imaging demonstrated new pulmonary and pancreatic lesions, which were histologically confirmed to be xanthogranulomatous disease. The patient was too unstable for surgical intervention so was commenced on glucocorticoids with marked improvement in his clinical condition with resolution of inflammatory markers and radiographic improvement. Weaning of prednisolone led to a relapse of disease, which was managed with re-introduction of high-dose prednisolone and the initiation of azathioprine. The patient is now 2 years post initiation of immunosuppressive therapy with stable renal function and no active inflammation.

Squamous cell carcinoma of the renal pelvis masquerading as xanthogranulomatous pyelonephritis.

We report a rare case of a 56-year-old male with a history of hypertension who initially presented to the emergency department with abdominal pain and was radiologically diagnosed with left xanthogranulomatous pyelonephritis (XGP) in a non-functioning kidney with a staghorn calculus. Pathological evaluation of his kidney revealed squamous cell carcinoma (SCC) of the renal pelvis with invasion into the renal parenchyma. We highlight the presentation, diagnosis, and management of this rare condition.

Incidentally found focal xanthogranulomatous pyelonephritis with extensive venous thrombus.

A 71-year-old woman with history of asthma presented with 2 months history of shortness of breath; on imaging an incidental left renal mass was noted. Subsequent renal protocol CT was obtained that showed a 4.5 cm left upper pole exophytic mass with renal vein thrombus extending into the inferior vena cava to the level of the caudate lobe concerning for renal cell carcinoma. She underwent an open left radical nephrectomy and IVC thrombectomy with subsequent postoperative pathology demonstrating xanthogranulomatous pyelonephritis without renal cell carcinoma.

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.

Xanthogranulomatous pyelonephritis infected with the Providencia stuartii: a case report and literature review.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is a rare and severe chronic inflammatory disease of the renal parenchyma, which is most commonly associated with super-infections by bacteria such as E. coli, Proteus mirabilis, and occasionally Pseudomonas species. CASE PRESENTATION: Herein, we present a rare case of a patient with XGP infected with Providencia stuartii. Initially, the patient refused nephrectomy and underwent holmium laser lithotripsy and right ureteral stenting, followed by meropenem treatment of 7 days. Relapse occurred in the third month after discharge from the hospital, due to which she underwent a radical nephrectomy. DISCUSSION: The diagnosis of XGP is confirmed by histopathology. The standard treatment for XGP is antibiotic therapy and radical nephrectomy, but partial nephrectomy may be appropriate in select cases.

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 with Pyonephrosis and Renal Abscess in a Young Adult: A Consequence of Neglected Urinary Tract Infection Leading to Nephrectomy.

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis, which is challenging to diagnose because its clinical presentation mimics other entities and is commonly associated with a history of urinary tract obstruction. We report a case of XGP in a young adult without nephrolithiasis and urinary tract obstruction. A 23-year-old woman presented with intermittent abdominal pain in the right upper quadrant persisting for the last ten months. The pain was dull, poorly localized, and started spreading to the right back, right shoulder, and right thigh in the last three months. Other complaints included fever, chills, pain during urination, and nausea. The patient had a history of infrequent urination, recurrent urinary tract infections (UTIs), and a low fluid intake. A physical examination revealed that the patient had right upper quadrant abdominal tenderness and right costovertebral angle tenderness. Laboratory findings showed leukocytosis and neutrophilia. The radiological examination revealed a round mass in the superior pole of the right kidney with mixed cystic and solid components, and a well-defined margin. It further enlarged from 4.5 cm to 10.6 cm in diameter in three months. The urologist performed a total right nephrectomy. The histopathological examination showed XGP with renal abscess. Proteus mirabilis was identified from the pus specimen culture. XGP should be considered in the diagnosis of patients having chronic UTI presented with or without the findings of urinary tract obstruction.

[Rare emergencies in urology]. / Les urgences rares en urologie.

INTRODUCTION: The aim of this article was to cite rare but sometimes serious emergencies that may be encountered by any urologist during their practice, and to outline the main principles of their management. MATERIAL AND METHOD: A systematic review of the literature using PubMed, Embase and Google Scholar was carried out between January 2000 and June 2021. The articles obtained were selected according to their age and type. The original articles, meta-analyses, recommendations and the most recent journal articles published in French and English have been retained. A total of 312 articles were identified and 58 selected from their abstracts. The articles were then analysed exhaustively by the authors, and 24 references were finally selected. RESULTS: Several rare emergencies of an infectious nature (xanthogranulomatous pyelonephritis, emphysematous cystitis and pyelonephritis, malacoplasia, hydatiduria), ischemic nature (Fournier's gangrene, penile calciphylaxis), or hemorrhagic nature (hemospermia, hemorrhages of the upper urinary tract or adrenal gland spontaneous hematoma), or at the origin of painful manifestations (spermatic colic, venous thrombosis of the penis), can pose diagnostic and therapeutic difficulties, in the absence of consensus concerning their management. CONCLUSION: These pathologies, rare but sometimes serious, must be recognized in order to not delay the treatment and to be able to reduce their morbidity and mortality. Combined with the constant improvement of our diagnostic and therapeutic arsenal, a better knowledge of these rare emergencies will help to preserve the functional and vital prognosis of patients.

Atypical focal xanthogranulomatous pyelonephritis without clinical symptoms presenting as infiltrative renal cancer: a case report and literature review.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is an uncommon form of chronic pyelonephritis. Most patients of XGP are diffuse in radiology and the clinical features are typical. CASE PRESENTATION: We present a case of 24-year-old female with the absence of symptoms and normal laboratory examinations. Contrast computed tomography and intravenous pyelography demonstrate infiltrative renal mass and renal cell carcinoma is presumed. Laparoscopic right radical nephrectomy is performed, but the final pathological result shows XGP. CONCLUSIONS: As far as we know, this is the first case report of XGP without any symptoms/signs and with normal laboratory examinations. The diagnosis of atypical XGP is challenging and preoperative renal mass biopsy should be considered in special cases.

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.

Nephron-sparing management of Xanthogranulomatous pyelonephritis presenting as spontaneous renal hemorrhage: a case report and literature review.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is an uncommon infectious disease of the kidney known to mimic other renal maladies. A rare presentation of this uncommon disease is spontaneous renal hemorrhage (SRH). CASE PRESENTATION: We report a case of XGP in a 58 year old woman who presented with abdominal pain, hematuria, and radiating left flank pain. CT scan was felt to be consistent with perirenal hemorrhage abutting a fat-containing renal mass. The patient was eventually taken to surgery for left partial nephrectomy. Pathology report returned as XGP, and the patient has no complications from this disease process at 8 month follow up. CONCLUSION: Our search of the literature shows XGP presenting as SRH to be a rare clinical entity. Furthermore, this is the first such case managed with a nephron-sparing approach. The "great imitator" XGP should be added to the differential for patients presenting with spontaneous renal hemorrhage.

Case report: Xanthogranulomutous pyelonephritis presenting as "Wilms' tumor".

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is a rare renal tumor that arises as a complication of chronic obstructive pyelonephritis of uncertain etiology. It is primarily an adult tumor seen occasionally in children associated with urinary tract obstruction due to congenital urological anomalies, nephrolithiasis, and recurrent urinary tract infections. Radiologically, it may show neoplastic features such as those seen in common pediatric renal malignancies like wilms' tumor and renal cell carcinoma. This overlap in radiological manifestation frequently leads to misdiagnosis and delay in appropriate intervention. We report a case of a 3 years old boy who presented with history of recurrent urinary tract infections and a left renal mass initially thought to be Wilms' tumor. CASE PRESENTATION: We present a case of a 3 years old boy admitted to the Pediatric oncology unit at Muhimbli National Hospital in Dar es Salaam, Tanzania with one year history of recurrent fever and urinary tract infection signs and symptoms refractory to antibiotic therapy. He was eventually found to have a left kidney mass detected at the District hospital by abdominal ultrasound performed to evaluate a flank mass that was felt by his mother. He was then referred to our unit for a suspicion of Wilms' tumor which finally turned out  to be a left kidney Xanthogranulomatous pyelonephritis. He underwent a successful left nephrectomy and was discharged from hospital in a stable clinical condition and remains asymptomatic at the time of submission of this case report. CONCLUSION: This case report underscores the need for clinicians attending a febrile child with a renal mass that can be confused with common pediatric renal malignancies such as Wilms' tumor to broaden their differential diagnosis. The case also underlines the significance of individualized patient evaluation because this patient would have otherwise received preoperative chemotherapy under the International Society of Pediatric Oncology (SIOP) guidelines if the diagnosis of Wilms tumor was not ruled out.

Segmental dilatation of ureter: Report of two cases.

Segmental dilatation of ureter is a giant, focal segmental ureteral dilatation producing an elongated and distorted ureter. Two children presented with this condition, one had ipsilateral megacalycosis and contralateral vesicoureteric reflux. The other had duplication of the kidney. The non-functioning lower moiety showed structure of xanthogranulomatous pyelonephritis.

Xanthogranulomatous pyelonephritis masquerading as a tumor in an infant.

Xanthogranulomatous pyelonephritis (XGP) is an uncommon form of chronic pyelonephritis and a well recognized entity. It is rarely seen in children and neonates. The preoperative diagnosis is difficult and the etiology is still obscure. The condition is mostly diagnosed on nephrectomy specimen. The focal form mimicking neoplastic condition is rare. A case of XGP is reported here in an 8 month old child in which case nephrectomy was done with the clinical diagnosis of malignant renal tumor. Various modalities of preoperative diagnosis of this entity with conservative approach are also discussed.