Xanthogranulomatous pyelonephritis

Laparoscopic approach for xanthogranulomatous pyelonephritis and pyonephrosis

INTRODUCTION

Xanthogranulomatous pyelonephritis (XGPN) is a rare form of chronic renal inflammation, caused by long-term obstruction of the urinary tract. Pyonephrosis is a severe suppurative complication of acute obstructive pyelonephritis. Although minimally invasive approaches have many advantages, the safe dissection of the kidney may not be always achievable.

MATERIALS AND METHODS

We reviewed 27 cases diagnosed with either XGPN or pyonephrosis, who underwent laparoscopic total nephrectomy between October 2016 and March 2022 in our department. All interventions were performed using the Karl Storz 3D laparoscopic system. The surgical approach was standard transperitoneal nephrectomy for the majority of XGPN, while pyonephrosis cases were carried out in a retroperitoneally. All procedures were performed or supervised by the same surgeon.

RESULTS

The mean operative time was 269.85 minutes (range 145-360). The mean hemoglobin drop after surgery was 1.41 g/dl (range 0.3-2.3 g/dl). Difficult dissection was encountered in 13 cases (48.14%). Nine out of 13 interventions were carried out in a complete intracorporeal fashion, while conversion to open surgery was needed in 4 cases. Vascular complications involving the major blood vessels comprised of one case of inferior vena cava (IVC) tear. Digestive tract-related complications comprised two fistulas of the descending colon and one peritoneal breach. Multiorgan resection was performed in 6 cases.

CONCLUSION

Total nephrectomy in cases of XGPN and pyonephrosis is a challenging procedure. The laparoscopic approach is feasible, as most complications are resolved intracorporeally. However, it may remain reserved for large-volume centers with experienced surgeons.

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.

Nephrectomy for xanthogranulomatous pyelonephritis-a not-so-simple solution

BACKGROUND

Xanthogranulomatous pyelonephritis (XGP) is a rare chronic inflammatory condition of the kidney, associated with high patient morbidity, often requiring targeted antibiotic therapy and surgical removal of the affected kidney.

AIM

We report the outcomes of patients undergoing nephrectomy for XGP in our institution over a 12-year period.

METHODS

Following ethical approval, a retrospective review of histological samples of renal tissue demonstrating features of XGP from June 2010 to 2022 was conducted. Laboratory, imaging, and clinical data of included participants were collected.

RESULTS

Eleven patients were included (8 women, 3 men), mean age of 58.1 (35-81). Recurrent urinary tract infection was the most common clinical presentation (55%, n = 6). Other presentations included flank pain (36%, n = 4), collection/ abscess (45%, n = 5), and nephro-cutaneous fistulae (9%, n = 1). The majority of patients had bacteriuria (91%, n = 10), and Escherichia coli was the most common bacteria isolated (55%, n = 6). Antibiotic resistance was seen in 60% of positive urine samples (n = 6). An open nephrectomy was performed in all but one case (91%, n = 10). A postoperative complication occurred in 73% (n = 8), with 50% (n = 4) of complications Clavien Dindo grade 3 or higher, including one patient mortality.

CONCLUSIONS

XGP is a difficult and complex condition to treat. All patients in this series presented with infection or associated sequelae thereof. Complex XGP cases therefore often require open nephrectomy and have high rates of postoperative complications. Careful consideration of antibiotic and operative intervention is therefore essential to ensure the best outcome for these patients.

Xanthogranulomatous Ureteritis: A Diagnostic Challenge in a Patient with Bladder Cancer

Xanthogranulomatous ureteritis is a very rare process characterized by the presence of foamy histiocytes in a background of chronic active inflammation affecting the ureteral wall. Herein, we describe a case of a 64-year-old man with bladder cancer affecting the left posterolateral wall of the bladder. Radiologically, there was a suspicion of multifocal involvement of the ureteral wall. The patient underwent a radical cystectomy with bilateral pelvic lymphadenectomy and a laparoscopic left nephroureterectomy. Histopathologic examination of the radical cystectomy revealed an invasive high-grade urothelial carcinoma. The wall of the left ureter was replaced by abundant foamy histocytes and a mixed inflammatory infiltrate with lymphocytes and plasma cells consistent with xanthogranulomatous ureteritis. In this report, we highlight the importance of awareness of this benign process when observing a ureteral mass in cancer patients.

Surgical correction of multiple renoduodenal fistulas due to chronic pyelonephritis: a case report and literature review

Renoduodenal fistulas are a rare and uncommon phenomenon that account for ˂1% of those found between the urinary and intestinal tracts. Precipitation of this pathologic tract can be caused by chronic inflammation, necrosis, or ischemia. This case illustrates a 72-year-old man presenting with flank pain discovered to have multiple renoduodenal fistulas and our approach that led to the resolution of his symptoms. We review the pathophysiology, management, and effects of these fistulous tracts on renal function. Patients with staghorn calculi should undergo immediate evaluation for removal of the stone. In cases complicated by fistula formation, need for radical nephrectomy should be investigated and surgical repair should be pursued.

Antemortem Diagnosis and Successful Long-term Management of Disseminated Intracoelomic Xanthogranulomatous Disease in an Eclectus Parrot (Eclectus roratus)

A 12-year-old male eclectus parrot (Eclectus roratus) was referred for evaluation of coelomic distention. Computed tomography and blood work revealed coelomic effusion with free coelomic mineral-attenuating material and elevations in the bile acids and aspartate aminotransferase activity, respectively. Coelomic effusion was consistent with macrophagic inflammation with abundant intracellular lipids. Initial treatment with meloxicam resulted in minimal patient improvement. Disseminated xanthogranulomatous inflammation was suspected based on imaging and diagnostic laboratory results, which were consistent with those previously reported. Biopsy samples of liver tissue and intracoelomic masses confirmed this diagnosis. Treatment was initiated with prednisolone 1 mg/kg/d for 6 months, followed by 0.5 mg/kg/d for 3 months. Clinical improvement was assessed based on owner evaluation, plasma bile acid concentrations, and repeated computed tomographic scans. After 2 months of treatment, the owner reported improved behavior and appetite; this persisted throughout treatment and when the bird was reexamined 17 months following the cessation of steroid therapy. Bile acid concentrations were normal 10 months after the prednisolone therapy was discontinued. Diagnostic imaging showed minimal coelomic effusion 10 months after the last prednisolone dose was administered, with improved ventilation of the air sacs and static to improved dystrophic mineral foci. This report describes the antemortem diagnosis and treatment of disseminated coelomic xanthogranulomatous disease in a psittacine species, with an observed measurable therapeutic response.

Primary Squamous Cell Carcinoma of the Renal Pelvis: A Rare Complication of Xanthogranulomatous Pyelonephritis

Xanthogranulomatous pyelonephritis is a rare disease resulting from chronic inflammation and infection of the renal parenchyma. It usually arises as a consequence of obstructive chronic pyelonephritis. Primary squamous cell carcinoma of the renal pelvis is a distinct pathology, very rare in clinical practice, with a well-established association with xanthogranulomatous pyelonephritis. The authors present the case of a 57-year-old woman with chronic pyelonephritis containing xanthogranulomatous features. Subsequent workup revealed a concomitant, unsuspected, primary squamous cell carcinoma of the renal pelvis. With this case, the authors intend to emphasize and reinforce the need to be alert to an uncommon association between two rare diseases due to its diagnostic, therapeutic, and prognostic implications.

Diffuse Xanthogranulomatous pyelonephritis: A Rare Disease With A Common Presentation

Xanthogranulomatous pyelonephritis (XGP) is a distinct entity characterized by chronic granulomatous changes in the renal parenchyma associated with renal destruction and urinary tract abnormalities, most often from obstruction or infection in the urinary tract. We have presented the case report of a girl with fever, abdominal pain, vomiting, anorexia, and weight loss. Computed tomography of the abdomen showed multiloculated cystic lesions with calcifications and a psoas muscle abscess, which tested positive for Escherichia (E.) coli. Histopathology revealed lipid-laden macrophages, multinucleated giant cells, and fibrosis. Nephrectomy and drainage of the psoas abscess were done. XGP, although rare, should not be confused with renal tumors and should be considered in children presenting with fever and urinary tract symptoms. Early diagnosis can be reached with CT. Nephrectomy is the definitive treatment.

Clinical Presentation, Microbiological Characteristics, and Their Implications for Perioperative Outcomes in Xanthogranulomatous Pyelonephritis: Perspectives from a Real-World Multicenter Practice

Xanthogranulomatous pyelonephritis (XGP) is an uncommon chronic granulomatous infection of renal parenchyma. XGP is often associated with long-term urinary tract obstruction due to stones and infection. We aimed to analyze the clinical, laboratory, and microbial culture profiles from bladder and kidney urine of patients who were diagnosed with XGP. Databases of patients with histopathological diagnosis of XGP from 10 centers across 5 countries were retrospectively reviewed between 2018 and 2022. Patients with incomplete medical records were excluded. A total of 365 patients were included. There were 228 (62.5%) women. The mean age was 45 ± 14.4 years. The most common comorbidity was chronic kidney disease (71%). Multiple stones were present in 34.5% of cases. Bladder urine culture results were positive in 53.2% of cases. Kidney urine culture was positive in 81.9% of patients. Sepsis and septic shock were present in 13.4% and 6.6% of patients, respectively. Three deaths were reported. Escherichia coli was the most common isolated pathogen in both urine (28.4%) and kidney cultures (42.4%), followed by Proteus mirabilis in bladder urine cultures (6.3%) and Klebsiella pneumoniae (7.6%) in kidney cultures. Extended-spectrum beta-lactamases producing bacteria were reported in 6% of the bladder urine cultures. On multivariable analysis, urosepsis, recurrent urinary tract infections, increased creatinine, and disease extension to perirenal and pararenal space were independent factors associated with positive bladder urine cultures. On multivariable analysis, only the presence of anemia was significantly more frequent in patients with positive kidney cultures. Our results can help urologists counsel XGP patients undergoing nephrectomy.

MDCT Diagnosis and Staging of Xanthogranulomatous Pyelonephritis

Background: Benign nephrectomy to treat patients with renal inflammatory disease in cases of severe urinary infection represents a diagnostic and management challenge because of significant inflammatory, fibrotic, and infectious components. Among renal inflammatory diseases, fistulization and invasiveness to adjacent structures are some of the hallmarks of xanthogranulomatous pyelonephritis (XGP). The aims of this study were as follows 1. to retrospectively determine key demographic and clinical features of XGP among benign nephrectomies; 2. to assess the CT preoperative diagnostic accuracy; and 3. to define the imaging characteristics of the CT stage. Material and Methods: A retrospective review of clinical, laboratory, and radiological features and operative methods of patients who underwent benign nephrectomy with histologically proven XGP was performed. Results: XPG was diagnosed in 18 patients over a 4-year (2018–2022) period. XGP represented 43.90% among benign nephrectomies. The mean age of the patients was 63 years, and the sex prevalence was higher in women (72.22%). Symptoms were vague and not specifically referrable to urinary tract disorders and unilateral (100%), with the left kidney affected in 61.11% of cases. Staghorn calculi and stone disease were the most common underlying cause (72.22%). All patients underwent CT. The preoperative CT imaging accuracy for renal inflammatory disease was 94.44% and indeterminate in 5.56%. A suspected diagnosis of XGP was formulated in 66.67% (12/18; 2 stage II/10 stage III), meanwhile, in 33.33% (6 patients with stage I), a non-specific diagnosis of renal inflammatory disease was formulated. CT was reported according to the Malek and Elder classification and staged in the stage I nephric form (33.33%), stage II perinephric form (11.11%), stage III paranephric form (55.56%). Conclusions: The CT diagnostic accuracy for kidney inflammatory disease was extremely high, whereas the suspected diagnosis of XGP was formulated preoperatively in only 66.67% of high-stage disease, where the hallmarks of invasiveness and fistulization of the pathology increased the diagnostic confidence.

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.

Concurrent Xanthogranulomatous Pyelonephritis and Upper Urinary Tract Transitional Cell Carcinoma

A 37-year-old male with a history of chronic nephrolithiasis presented to the ED with gross hematuria, clot retention, and right flank pain. The patient had radiological findings of perinephric stranding, marked hydronephrosis, and marked thinning of the right renal parenchyma on computed tomography (CT), all suggestive of xanthogranulomatous pyelonephritis (XGP). The specimen following radical nephrectomy revealed urothelial carcinoma (UC) in a background of XGP but with no evidence of spread to regional lymph nodes. Follow-up imaging revealed hypodense lesions in the liver which demonstrated UC on biopsy. This is the first reported case of a young patient presenting with such an advanced stage of UC in the setting of XGP. It illustrates the link between inflammatory processes of the kidney and malignancy of the upper urinary tract.

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.

A Rare Case of Unilateral Xanthogranulomatous Ureteritis Mimicking an Inferior Vena Cava Tumor

Xanthogranulomatous pyelonephritis (XPG) is a known clinical entity; however, the further progression of this inflammatory pathology to adjacent organs, including the ureter, bladder and urethra, is extremely rare. Xanthogranulomatous inflammation of the ureter is a chronic inflammatory state where foamy macrophages are seen in the lamina propria along with multinucleated giant cells and lymphocytes forming a granulomatous inflammation, which is benign. Based on its appearance on computed tomography (CT) scan images, it can easily be misidentified as a malignant mass, and the patient can be subjected to surgery that can lead to complications. Here we present a case of an elderly male with a known case of chronic kidney disease with uncontrolled type 2 diabetes mellitus who presented with fever and dysuria. Upon further radiological investigations, the patient had underlying sepsis and was seen to have a mass involving the right ureter and inferior vena cava. Upon biopsy and histopathology, he was diagnosed with xanthogranulomatous ureteritis (XGU). The patient underwent further treatment and was followed up.

“Uroptysis!” – A case report of xanthogranulomatous pyelonephritis with nephrobronchial fistulation

Introduction and importance

Xanthogranulomatous pyelonephritis (XGP) is an uncommon complication of chronic urinary tract infection, classically secondary to a chronic obstructive uropathy, resulting in destruction of renal parenchyma and a non-functioning kidney (Jha and Aeddula, 2022 [1]). This is rarely associated with nephrobronchial fistulation, with few published case reports in the literature to date.

Case presentation

We present the rare case of a 42-year-old female who was admitted to an Irish tertiary urology centre with abdominal pain, elevated inflammatory markers and an obstructive uropathy on initial imaging, with a new diagnosis of XGP. Initial management was with targeted intravenous antimicrobial therapy, percutaneous nephrostomy and perinephric drain insertion. The subsequent discovery of a nephrobronchial fistula later complicated the case, warranting plan for interval nephrectomy and fistula repair following prolonged medical management. We discuss the initial presentation, workup and image-guided approach to management.

Clinical discussion

XGP is an uncommon sequela of chronic renal suppurative infection, and is usually associated with long-standing ureteric obstruction secondary to a staghorn calculus. Nephrobronchial fistulation is a rare complication of XGP, highlighting the significance of this case discussion.

Conclusion

XGP should be considered in cases of suspected chronic pyelonephritis and may rarely lead to nephrobronchial fistulation. In cases of known XGP and pleural empyema, nephrobronchial fistulation should be considered as part of the differential diagnosis.

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Xanthogranulomatous pyelonephritis is rare and associated with chronic upper urinary tract infection and obstruction.

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Nephrobronchial fistulation is a rare complication of xanthogranulomatous pyelonephritis.

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In cases of XGP and concurrent pleural empyema, a nephrobronchial fistula should be considered.

Perioperative predictors for complications in patients with Xanthogranulomatous Pyelonephritis treated with nephrectomy

Introduction:

Xanthogranulomatous pyelonephritis is an inflammatory disease characterized by chronic obstruction and infection. This pathology is a life-threatening condition when surgical treatment is carried out. We decided to retrospectively evaluate whether there were perioperative factors that predict complications in patients who undergo nephrectomy.

Methods:

We reviewed all nephrectomies done in the period of 2013–2018, in a tertiary referral Hospital with the histopathological diagnosis of Xanthogranulomatous Pyelonephritis.

Results:

The presence of renal abscess at admission was observed as a risk factor associated with perioperative complications ( p = 0.002), presence of abscess was observed in 47.4% of subjects without complications compared to 89.3% of the perioperative complication group. Higher rates of blood transfusion requirement were observed in the perioperative complication group, 89.3% compared to 68.4% ( p = 0.029), furthermore, perioperative bleeding was slightly greater in the complication group compared to its counterpart, 700 mL, and 600 mL, respectively ( p = 0.01).

Conclusions:

Anemia and the presence of abscess were important perioperative factors that predict perioperative complications.

Xanthogranulomatous Oophoritis in the Setting of Post-IVF Twin Pregnancy with History of Endometriosis: A Rare Case Report with Review of Literature

Xanthogranulomatous inflammation is an uncommon, nonneoplastic, chronic process in which the affected organ is destroyed by massive cellular infiltration of foamy histiocytes admixed with multinucleated giant cells, plasma cells, fibroblasts, neutrophils, and foci of necrosis. The organs most commonly affected by this entity are kidney and gallbladder. Only a few cases involving the ovary have been reported. The etiology of this entity is unknown, but the associated risk factors are infection, inappropriate antibiotic therapy, use of intrauterine contraceptive device, abnormalities in lipid metabolism, endometriosis, leiomyoma, and recurrent pelvic inflammatory disease. The current case was a 31-year-old female with post-in vitro fertilization (post-IVF) twin pregnancy, who presented with pain in the abdomen, provisionally diagnosed as ovarian mass with suspicion of malignancy. Patient was treated with antibiotics and an elective lower segment cesarean section was planned, due to lower abdominal pain and the presentation of both fetuses being breech. Patient underwent exploratory laparotomy with right oophorectomy and left double-J stenting, in view of left hydronephrosis. Diagnosis of xanthogranulomatous oophoritis was established on histopathological examination. There is only a single case; previously documented from India, in the setting of primary infertility. The present case report stresses that the condition may affect women of any age group and may be encountered in pregnancy, as has been observed in this case. Hence, thinking about this differential diagnosis in the cases presenting with similar complaints, would be of great value to avoid misdiagnosing them.

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.

[Basic nephropathology for pathologists-part 1 : Kidney biopsy-inflammation and immune complexes]

The assessment of kidney biopsies is mainly confined to specialized centres. However, sometimes a kidney biopsy is submitted to a general pathologist, and in addition peritumorous renal parenchyma in tumour nephrectomies can have concomitant non-neoplastic renal disease. Here we present a survey of inflammatory and immunologic changes in all renal compartments, which may in part indicate the need of prompt therapeutic intervention such as in vasculitis, glomerulonephritis and interstitial nephritis. It is important to take into account that renal involvement of vasculitis is mainly centred in glomeruli and only to a much lesser extent in arteries, and that the frequently observed interstitial inflammation very often is an epiphenomenon of another primary kidney disease and not an independent disease process. Typical renal patterns of injury are emphasised.

Neonatal Urinary Tract Infection and Renal Nodular Lesion: A Rare Case of Xanthogranulomatous Pyelonephritis

Xanthogranulomatous pyelonephritis (XPN) is an uncommon variant of chronic pyelonephritis with a poorly understood pathogenesis and a challenging diagnosis. It is rare in pediatric patients, particularly in the neonatal period. We report the case of an 18-day-old female neonate admitted to the emergency room due to macroscopic hematuria and poor feeding. Urinalysis revealed leukocyturia and she was initially admitted under the clinical suspicion of acute pyelonephritis. Renal ultrasound and magnetic resonance imaging (MRI) revealed a progressive nodular lesion in the middle third of the left kidney. Given the suspicion of renal abscess or neoplasm, the patient was transferred to our tertiary hospital. Urinary catecholamines and tumor markers had normal values. Percutaneous kidney biopsy confirmed XPN. Posterior computed tomography scan excluded extension to neighboring structures. A conservative management with systemic antibiotic therapy was decided. She completed 7 weeks of systemic antibiotic therapy (ampicillin and cefotaxime) with progressive reduction of lesion size and posterior calcification. Follow-up at 3 years was uneventful. The lipid profile and study of neutrophil function were normal. Voiding cystourethrography excluded vesicoureteral reflux. The authors intend to highlight the importance of a high index of suspicion of XPN to allow preoperative diagnosis. Histopathological assessment is mandatory to confirm XPN and exclude other entities mimicked by focal and unilateral progressive disease. There are only a few published cases of optimal clinical evolution solely with broad-spectrum antibiotics; however, this may allow a beneficial nephron-sparing approach in selected patients.

Case report: Localized xanthogranulomatous pyelonephritis in children: A case report and literature review

BACKGROUND

Xanthogranulomatous pyelonephritis (XGPN), which is featured by inflammatory destruction of renal parenchyma and fibrosis of kidney, occurs mainly among adults, sporadically among children and rarely among infants. Recurrent urinary tract infections, kidney stone-induced obstructive nephropathy, malnutrition, abnormal lipid metabolism, hypoimmunity, lymphatic obstruction and congenital urinary abnormalities may all cause XGPN among children. Its primary treatment is radical nephrectomy.

CASE DESCRIPTION

In this study, we describe a rare case of XGPN in a 7-year-old boy infected with Staphylococcus aureus (S. aureus). The child presented with symptoms including recurrent fever, urine culture negative. The postoperative pathology confirmed XGPN. Besides, partial nephrectomy was performed.

CONCLUSION

XGPN, as a special type of chronic pyelonephritis, is a rare pyelonephritis requiring surgical treatment. Early diagnosis and treatment are crucial to reducing its morbidity and mortality. Although radical nephrectomy is the primary therapeutic option for patients with XGPN, partial nephrectomy surgery should be considered for focal XGPN, aiming to preserve residual renal function in children as far as possible.

Retroperitoneal abscess caused by dropped renal stones

Staghorn calculi account for about 4% of presenting renal stones in developed countries, are source of recurrent urinary tract infection, and may be eventually treated by surgical stone removal. A 55-year-old female with a history of staghorn renal calculi and recurrent urinary tract infections presented with a left flank and lower abdominal pain following recent left robotic partial nephrectomy and nephrolithotomy. Contrast-enhanced computed tomography (CT) of the abdomen demonstrated a large left-sided retroperitoneal fluid collection with a few dropped renal stones in the dependent portion of the collection. The patient treated with early percutaneous drainage of the collection and antibiotic treatment and responded well clinically. The clinical and imaging presentation of a rare case of retroperitoneal abscess formation caused by dropped renal stones is described in this study. Imaging, particularly ultrasound and CT, plays a key role in detecting the dropped renal stones and can help with differential diagnosis and treatment plans.

Xanthogranulomatous pyelonephritis combined with emphysematous pyelonephritis: A rare case report

Background:

Xanthogranulomatous pyelonephritis (XGP) is a rare and intense type of chronic kidney infection characterized by subversion of the renal tissue and its replacement by lipid- laden macrophages. XGP combined with emphysematous pyelonephritis(EPN) is rare and up until now only 7 cases with these presentations have been reported; so abundant clinical skills and appropriate radiographic imaging is required to reach the correct diagnosis. In this report, we present a case with two uncommon variants of pyelonephritis.

Case Presentation:

A 55-year-old female presented with a history of type 2 diabetes mellitus, and a stroke leading to a left-sided hemiplegia state for 7 years, coronary artery bypass grafting(CABG), hypertension(HTN) , seizure, progressive fatigue, loss of appetite , fecal and urinary incontinence and right costovertebral angle tenderness. According to clinical signs, symptoms and documentation of gas within the renal parenchyma on computed tomography (CT) of abdomen, of EPN diagnosis was suggested; however histopathologic evaluation showed acute emphysematous pyelonephritis on chronic xanthogranulomatous pyelonephritis.

Conclusion:

EPN can emerge in a patient suffering from XPG which would add to the severity of the situation. In the case presented, concurrent underlying diseases such as diabetes mellitus, stroke, CABG, HTN along with severe fatigue and loss of appetite existed. Surgical treatment produces dramatic results.

Xanthogranulomatous Pyelonephritis and Its Differential Diagnoses: An In-Depth Case Review

Xanthogranulomatous pyelonephritis is a rare chronic infectious process of the kidney, which has been described in three different forms: diffuse, segmental, and focal. It is also known as the great simulator since its clinical, radiological, and histopathological manifestations tend to be confused with other entities. We describe a case of a 55-year-old male patient with two months of clinical manifestations characterized by a 7x7-cm palpable mass in his right lumbar region, which was hot and painful upon touch and increasing in size. This article aims to present a case of xanthogranulomatous pyelonephritis and compare it with its primary differential diagnoses. It is evident that despite the condition being considered a simulating pathology, some key differences can be found to identify and distinguish it.

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.

Xanthogranulomatous Pancreatitis Accompanied by Xanthogranulomatous Cholecystitis: A Case Report and Literature Review

ABSTRACT

Xanthogranulomatous pancreatitis (XGP) is extremely rare, with only 31 cases reported in the English literature to date. We reviewed previously reported 17 articles about XGP and report an additional case of XGP. This is the first case of XGP with xanthogranulomatous cholecystitis accompanied by intraductal papillary mucinous carcinoma (IPMC) in an 80-year-old woman. She was referred to our hospital with jaundice and general malaise and was found to have a cystic mass at the pancreatic head and a solid mass at the pancreatic tail, with dilation of both the main pancreatic duct and biliary tract noted on computed tomography. Diagnosis of IPMC at the pancreatic head with neuroendocrine tumor at the pancreatic tail was made, and the patient underwent subtotal stomach-preserving pancreatoduodenectomy with enucleation of the mass at the tail. Pathological examination revealed IPMC with xanthogranulomatous changes around the IPMC and at the pancreatic tail and gallbladder. Xanthogranulomatous pancreatitis could be induced by inflammatory reaction due to obstruction of the pancreatic duct and biliary tract by mucin produced in the IPMC. It is sometimes difficult to preoperatively differentiate XGP from malignant pancreatic tumors, such as pancreatic carcinoma or neuroendocrine tumor, using imaging studies.

Xanthogranulomatous pyelonephritis with calculus migration into the psoas abscess: an unusual complication

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of chronic pyelonephritis. It is characterized by progressive parenchymal destruction caused by chronic renal obstruction due to calculus, stricture, or rarely tumor, resulting in kidney function loss. Herein, we describe the case of a 36-year-old female who presented with left loin pain, left lower limb pain, and dysuria. On contrast-enhanced computed tomography (CECT), multiple abscesses and an obstructive staghorn calculus were depicted in the left kidney with the classical appearance of “Bear Paw Sign.” An abscess with calculi was also present within the left psoas muscle. Though psoas muscle abscess in association with XGP was described, a ureteric fistula and calculi within the psoas muscle have not yet been reported in the literature. Left nephrostomy was performed, which came out to be positive for E. coli on culture. The patient underwent left nephrectomy, and the histopathological report of the surgical specimen confirmed XGP.

Xanthogranulomatous pyelonephritis presenting as a cystic mass: a rare case report

Xanthogranulomatous pyelonephritis may, rarely, occur as a renal cystic mass. We report a case report of a 50-year-old with a history of medically treated renal lithiasis, who consults for left low back pain. Imaging findings concluded to a Bosniak type-3 hemorrhagic cystic mass of the left kidney. The diagnosis of xanthogranumolatous pyelonephritis on its focal form was made histologically. The diagnosis of xanthogranulomatous pyelonephritis is often difficult even with surgical findings and frequently a histological surprise. This points out the importance of identifying it in pre-operative staging; the diagnosis may be suggested by the association of chronic pyelonephritis, renal stones and hypovascular renal tumor syndrome without specificity at sonography and CT.

Horseshoe Kidney Complicated by Xanthogranulomatous Pyelonephritis in a Young Girl: A Case Report and Review of the Literature

The cases of horseshoe kidney presented by xanthogranulomatous pyelonephritis are very rare. In this study, the case of XGP developing in HSK in a young female patient was presented due to its rare incidence and the previously reported cases were reviewed, as well. The patient, who has end-stage renal disease and was under treatment, admitted to the clinic for preemptive kidney transplantation. Bilateral open en bloc nephrectomy was performed before the kidney transplantation. The histopathological examination of the specimen was reported as XGP. Eight months later, living-donor organ transplantation was performed to the patient with the kidney obtained from her father. XGP can present as a complication of HSK. Moreover, HSK may rarely be manifested by end-stage renal disease in young patients. In such cases, who would undergo kidney transplantation, it is important to examine the HSK in detail and perform bilateral nephrectomy to prevent complications after transplantation.

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.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

[Renal granulomatous nephritis: Histopathological point of view]

Granulomatous interstitial nephritis (NIG) is a rare form of interstitial nephritis that can be related to acute or chronic clinical presentation. NIG is characterized by granulomas located to the renal interstitium and composed of either epithelioid histiocytes with giant cells and/or of foreign body reaction. The symptoms are unspecific and associate varying degrees of renal failure with abnormal urinanalysis. Extra-renal signs may point to systemic disease. Pathological examination from kidney percutaneous biopsy or surgical resection is required to assert NIG diagnosis and to guide the etiological research. The main causes of NIG are sarcoidosis, drug reactions, mycobacterial infections and crystalline nephropathies. Sarcoidosis is characterized by non-necrotic and well-formed giant cell epithelioid interstitial granulomas. Drug reactions have less well-defined granulomas with inconstant eosinophils. The presence of caseous necrosis within giant cell and epithelioid granulomas leads to infectious NIG diagnosis (tuberculosis and fungal infection). Identification of crystals within foreign body reaction can be improved by polarized light study. Xanthogranulomatous pyelonephritis and malakoplakia are rarer causes of NIG characterized by patches of histiocytes associated with inconstant giant cells. Differential diagnoses of NIG are represented by granulomatous reactions centered on glomeruli and vessels (vasculitis and emboli of cholesterol crystals). Less than 10% of NIG are idiopathic. The prognosis and the treatment vary according to the cause. The factors of poor renal prognosis are chronic irreversible tubulo-interstitial injury (tubular atrophy and interstitial fibrosis).

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.

Imaging of Renal Infections and Inflammatory Disease

Acute pyelonephritis is a bacterial infection of the renal parenchyma and collecting system. Diagnosis is based on clinical findings of fever, flank pain, and urinary tract infection. Computed tomography findings include renal enlargement with wedge-shaped heterogeneous areas of decreased enhancement, known as a "striated nephrogram." Imaging is primarily used to diagnose complications such as emphysematous pyelonephritis, renal abscess, and pyonephrosis. Chronic pyelonephritis can have varying appearances on imaging ranging from xanthogranulomatous pyelonephritis or, in extreme cases, renal replacement lipomatosis.

A rare presentation of xanthogranulomatous pyelonephritis and emphysematous pyelonephritis complicated with necrotizing fasciitis of scrotum and perineum (fournier gangrene)

We report a case of cooccurrence of xanthogranulomatous and emphysematous pyelonephritis along with necrotizing fasciitis (NF) of scrotum and premium in a patient was nondiabetic and the history of kidney stones. This case a unique presentation of NF due to two pyelonephritis causing fournier gangrene. Surgical management and antibiotics provide an effective management of the disease.

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.

Xanthogranulomatous Ureteritis Mimicking Ureteral Involvement by Cancer in a Radical Cystectomy Specimen

Xanthogranulomatous pyelonephritis is well established as a renal mass-forming inflammatory process. However, a ureteral counterpart is minimally recognized. In this article, we present a case of xanthogranulomatous ureteritis in an 81-year-old woman, mimicking ureteral involvement by cancer in a radical cystectomy specimen for invasive urothelial carcinoma. Similar to the pathogenesis of xanthogranulomatous pyelonephritis, the patient was noted to have ureteral obstruction by calculus and had urine culture positive for Klebsiella pneumoniae. To our knowledge, this is the first report of xanthogranulomatous ureteritis associated with this pathogen and the only report associated with concurrent bladder cancer. Increased pathologist and urologist awareness of xanthogranulomatous ureteritis expands the spectrum of pseudotumoral processes of the ureter.

Case report: Xanthogranulomatous pyelonephritis masquerading as cystic renal cell carcinoma

Background: Xanthogranulomatous pyelonephritis (XGP) is a rare chronic bacterial inflammation of the renal parenchyma and is often a diagnostic dilemma.Case Presentation: We present a challenging case of a patient with XGP. Initially thought to have had renal cell cancer she was treated accordingly with a partial nephrectomy. However, on the final pathology, she was found to have XGP and required further antibiotic therapy and referral to the infectious disease service.Discussion: Management of XGP and diagnostic pitfalls are discussed.Conclusion: XGP is a diagnostic and therapeutic dilemma. Partial Nephrectomy may be appropriate in management of XGP in select cases.

Xanthogranulomatous pyelonephritis with associated renal cell carcinoma

Xanthogranulomatous pyelonephritis is associated with obstruction, stones and infection. CT is the mainstay of diagnosis, but appearances can mimic other conditions, including renal cell carcinoma. Nephrectomy is commonly recommended, but conservative treatment with antibiotics has been described after tissue diagnosis. We present a case of xanthogranulomatous pyelonephritis with concomitant renal cell carcinoma, which was an association that was suggested in 1988 and supported by subsequently reported cases. Conservative management of biopsy or cytology proven xanthogranulomatous pyelonephritis is unsafe, as an area of synchronous malignant tumour may be missed: we recommend it only in patients unfit for nephrectomy.

Ultrastructural evidence of the evolutional process in malakoplakia

CONTEXT

Malakoplakia can be caused by incomplete digestion of Escherichia coli by lysosomes, leading to recurrent urinary tract infections and consequential mass-forming events that mimic tumors.

OBJECTIVES

By using ultrastructural findings, we aimed to specify the process of phagolysosome to evoke malakoplakia.

DESIGN

We observed a series of processes to form a peculiar Michaelis-Gutmann (MG) body in three patients with malakoplakia and compared with xanthogranulomatous pyelonephritis.

RESULTS

The ultrastructural findings were realigned according to the sequence of events as pre-phagosomal, phagosomal, and post-phagosomal stages. For the mature MG body, numerous lysosomal aggregates targeting pathogens and subsequent incomplete digestion are prerequisite factors for the pre-phagosomal stage. Scattered lamellated residue is late evidence of the pre-phagosomal stage. Phagosomes can be formed by the fusion of multiple pathogens and multiple lysosomes. We utilized transmission and scanning electron microscopy to speculate on the process of phagolysosomal formation.

CONCLUSION

The recognition of E. coli captured by phagosomes or partially damaged by lysosomal attack within the cell was recorded for the first time. Furthermore, SEM observation was performed on human tissue.

Postpartum xanthogranulomatous pyelonephritis: A case report

Xanthogranulomatous pyelonephritis (XGP) is seldom seen nowadays due to the aggressive treatment of upper urinary tract infections as well as recent advances in the management of urolithiasis. It has been rarely reported in the peri-partum period. We present a case of XGP without any evidence of renal calculi, manifesting in a 26-year-old previously healthy woman immediately post-partum.

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Xanthogranulomatous pyelonephritis is rare due to the aggressive treatment of upper urinary tract infections and urolithiasis.

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It has been rarely reported in the peri-partum period.

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A post-partum 26-year-old woman developed acute xanthogranulomatous pyelonephritis, without any evidence of renal calculi.