[A Case of Xanthogranulomatous Pyelonephritis with Multiple Lymphadenopathy that was Difficult to Differentiate from Renal Tumor].

A 74-year-old woman presented to our hospital with the main complaint of anorexia and weight loss for several months. Computed tomography (CT) revealed right urinary stone, hydronephrosis, multiple lymphadenopathy, and a mass in the right kidney. Considering these findings, she was suspected to have renal malignancy (kidney or renal pelvis cancer) with multiple lymph node metastases; therefore, nephrectomy was performed. Her pathological diagnosis was xanthogranulomatous pyelonephritis (XGPN). There was no postoperative renal function decline, and multiple lymphadenopathy also disappeared on CT 3 months after surgery. It was judged to be reactive swelling due to inflammation. XGPN is a pathological condition characterized by accumulation of mast cells and activated macrophages in the renal tissue; and, the renal tissue recognizes yellowish granulation growth because of repeating pyelonephritis due to urinary tract passing impairment. In some cases, it is difficult to differentiate XGPN from renal malignancy. Moreover, lymphadenopathy may be lymph node metastasis but may also present reactive enlargement due to the effect of inflammation, making it even more difficult to differentiate when accompanied by lymphadenopathy. We report this case in which it was difficult to differentiate XGPN from renal malignancy considering the scarcity of reports of XGPN accompanied by multiple lymphadenopathy.

Systemic Amyloid A Amyloidosis Secondary to Xanthogranulomatous Pyelonephritis.

The combination of systemic amyloid A (AA) amyloidosis and xanthogranulomatous pyelonephritis (XGP) resulting from a chronic urinary tract infection is extremely rare. We herein report a case of systemic AA amyloidosis secondary to XGP for which clinical remission developed after nephrectomy. To our knowledge, this is the first case report describing the clinical improvement of systemic AA amyloidosis secondary to XGP after nephrectomy in Japan. Clinicians should be aware of this uncommon combination and search for amyloid depositions in cases of XGP.

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.

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.

I saw the "bear paw" sign - Massive renal xanthogranulomatous pyelonephritis.

The bear paw sign is a radiologic sign seen on computed tomography (CT) that indicates the development of xanthogranulomatous pyelonephritis (XGP). It refers to the multiple, rim-enhancing, low attenuation renal collections seen in the diffuse form of XGP. The term "bear paw" sign first appeared in the literature in 1989 and has since been widely used to describe this serious, but treatable, pathology.

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.

Focal Xanthogranulomatous Pyelonephritis on FDG PET/CT.

ABSTRACT: Xanthogranulomatous pyelonephritis is a rare disease that was often accompanied with urinary obstruction. The focal form of xanthogranulomatous pyelonephritis is frequently misdiagnosed as malignancy. Here we present FDG PET/CT findings of a case focal xanthogranulomatous pyelonephritis in a 66-year-old woman with polycystic liver and kidney disease. The image showed a polycystic mass in the inferior pole of right kidney with high FDG uptake in the cystic wall, which was suggestive of a cystic renal carcinoma. Right radical nephrectomy was subsequently performed. The postsurgical pathology revealed xanthogranulomatous pyelonephritis.

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.

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.

Malakoplakia and xanthogranulomatous pyelonephritis treated with nephrectomy: A case report.

RATIONALE: Malakoplakia and xanthogranulomatous pyelonephritis are chronic inflammatory conditions of the kidney characterized by the infiltration of inflammatory cells. PATIENT CONCERNS: An 82-year-old female patient had a history of hypertension, type 2 diabetes mellitus, dyslipidemia, and end-stage renal disease under hemodialysis. She was admitted repeatedly 4 times within 4 months due to urosepsis. DIAGNOSIS: The enlarged right kidney with a low-density lesion at the right middle calyx, and a well-enhanced ureter were noted on the computed tomography scan. Therefore, xanthogranulomatous inflammation was suspected. Semi-rigid ureteroscopy with biopsy was performed, and xanthogranulomatous inflammation of the ureter was confirmed on the pathology report. INTERVENTIONS: After right open radical nephrectomy was performed, the final pathology report revealed malakoplakia with xanthogranulomatous pyelonephritis. OUTCOMES: After the surgery, she has no longer suffered from urosepsis for 8 months, and there were no adverse event or recurrence noted. LESSONS: With this case report, we aim to emphasize that these 2 diseases are not mutually exclusive, but they may exist simultaneously in the same patient.

Imaging Characterization of Renal Masses.

The detection of a renal mass is a relatively frequent occurrence in the daily practice of any Radiology Department. The diagnostic approaches depend on whether the lesion is cystic or solid. Cystic lesions can be managed using the Bosniak classification, while management of solid lesions depends on whether the lesion is well-defined or infiltrative. The approach to well-defined lesions focuses mainly on the differentiation between renal cancer and benign tumors such as angiomyolipoma (AML) and oncocytoma. Differential diagnosis of infiltrative lesions is wider, including primary and secondary malignancies and inflammatory disease, and knowledge of the patient history is essential. Radiologists may establish a possible differential diagnosis based on the imaging features of the renal masses and the clinical history. The aim of this review is to present the contribution of the different imaging techniques and image guided biopsies in the diagnostic management of cystic and solid renal lesions.

A rare case of ureteric involvement in xanthogranulomatous pyelonephritis associated with giant ureteric calculus: An unusual entity.

Xanthogranulomatous pyelonephritis (XGPN) is an uncommon chronic destructive granulomatous inflammation of the kidney with variable clinical and radiological presentation. Due to its similarities to other benign and malignant pathologies, a high index of suspicion is required for preoperative diagnosis, which will ensure appropriate management of this condition. The invasion into the surrounding structures such as pararenal spaces, psoas muscle, small bowel, diaphragm, lung or soft tissues has been reported. However, involvement of ureter is very rarely reported. We report a rare case of left-sided gross hydronephrosis with staghorn calculus with giant uretic calculi, postnephrectomy on the biopsy diagnosis of XGPN was made, which also revealed involvement of ureter also.

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.