[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.

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.

Clear Cell Renal Cell Carcinoma with Immunotherapy Effect Mimicking Xanthogranulomatous Pyelonephritis.

Renal cell carcinoma is now increasingly treated with checkpoint inhibitor therapy, predominantly in the metastatic setting or occasionally in the adjuvant setting; however, there is little published histopathology data demonstrating the post-therapy features of renal cell carcinoma tumor tissue. We report a middle-aged man, who was undergoing treatment with pembrolizumab for locally recurrent cutaneous basal cell carcinoma and was incidentally found to have a renal mass. Radical nephrectomy demonstrated a 5.0 cm renal mass with extensive xanthogranulomatous features, mimicking xanthogranulomatous pyelonephritis. However, rare clusters of cells demonstrated gland-like lumina, clear cytoplasm, and slightly increased atypia, suggesting scant residual renal cell carcinoma cells. Immunohistochemistry demonstrated focal positivity for pan-keratin and keratin 8/18, EMA, PAX8, CD10, and carbonic anhydrase 9 (CA9), supporting a diagnosis of renal cell carcinoma with extensive treatment response, to the point that it mimicked xanthogranulomatous pyelonephritis. This report demonstrates the histologic features of post-immunotherapy renal cell carcinoma, aiding pathologists in recognition of this phenomenon, which may be misdiagnosed as an inflammatory process, if immunotherapy was performed for other reasons.

Xanthogranulomatous pyelonephritis in a pediatric patient.

INTRODUCTION: Xanthogranulomatous pyelonephritis consists of a chronic infectious and inflammatory process of the renal parenchyma, a variant of chronic obstructive pyelonephritis. It is more prevalent in middle-aged adults, rare in pediatric patients, with less than 300 cases reported in children worldwide. REPORT: Preschooler, aged 2 years and 11 months, male, with 2 months of abdominal distention, increased temperature and intense pallor, associated with microcytic anemia refractory to the use of ferrous sulfate. 1 week before, he had a bulging in his left flank and a hard palpable mass there. Imaging exams (ultrasound and tomography) revealed an overall enlargement of the left kidney, destruction of the renal parenchyma and intense calyceal dilation, forming the "bear's paw" sign, with a staghorn calculus in the pelvis. He underwent treatment with antibiotic therapy and total nephrectomy, with a specimen sent for pathological examination. DISCUSSION: a disease of uncertain incidence in the pediatric age group, xanthogranulomatous pyelonephritis is more prevalent in male children and affects mainly the left kidney, being frequently associated with the presence of stones. Clinically, it has nonspecific symptoms, the most common being abdominal distension and asthenia. Laboratory exams shows microcytic, leukocytosis, thrombocytosis and increased inflammation, pyuria, hematuria and proteinuria, in addition to bacterial growth in urine culture. The diagnosis is anatomopathological, but it can be hinted by contrasted CT scan, with the classical sign of the "bear's paw". Treatment may include nephrectomy and broad-spectrum antibiotic therapy.

Xanthogranulomatous pyelonephritis 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.

Non-invasive papillary urothelial carcinoma, low-grade of the renal pelvis mimicking a xanthogranulomatous pyelonephritis in a male patient: A case report and review of literature.

We report on a 31-year-old male patient with non-invasive papillary urothelial carcinoma, low grade of the renal pelvis disguised as xanthogranulomatous pyelonephritis. The only symptom of the patient was lower back pain. The initial renal-enhanced computed tomography, magnetic resonance imaging and contrast-enhanced ultrasonography showed that the right kidney had a benign lesion and this inflammatory lesion might be xanthogranulomatous pyelonephritis. A percutaneous renal biopsy was performed and histopathologic examination revealed a xanthogranulomatous pyelonephritis. Initially, we diagnosed it as xanthogranulomatous pyelonephritis and treated it with antibiotics. One and a half years later, the patient suffered from back pain again. The lesion increased significantly and a right renal pelvic lesion with retroperitoneal lymphadenopathy was considered a malignant lesion on computed tomography scan. Therefore, radical resection of right renal pelvis carcinoma was performed under retroperitoneal laparoscopy. Intraoperative frozen section was reported as right renal urothelial carcinoma with no metastasis in renal hilar lymph node. Postoperative histopathologic examination revealed non-invasive papillary urothelial carcinoma, low grade of renal pelvis.

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.

Symmetric nephromegaly.

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

Xanthogranulomatous pyelonephritis in adults: clinical, biological, radiological and therapeutic main findings in diffuse and focal forms. About 42 cases.

INTRODUCTION: Xanthogranulomatous pyelonephritis (XGPN) is a particular form of chronic renal suppuration characterized by the destruction of renal parenchyma and its replacement by a granulomatous tissue containing xanthomatous cells. OBJECTIVE: To report and describe the main clinical, biological, radiological and therapeutic aspects of xanthogranulomatous pyelonephritis in adults in focal and diffuse forms. METHODS: This was a monocentric retrospective study involving 42 cases of XGPN operated and histologically confirmed between 2005 and 2015. We included in our study the patients belonging to any age, of both sexes, with a preoperative CT and whose XGPN diagnosis was confirmed histologically. Clinical, biological, bacteriological, radiological data and surgical procedures were collected and analyzed. RESULTS: The mean age was 50 years (34-79) with a sex ratio of 0.61. The XGPN was diffuse in 88% and focal in 12% of cases. Clinical symptoms were dominated by low back pain (95%), fever (64%) and recurrent urinary tract infections (41%). Urine culture was positive in 67% of cases and Escherichia Coli was the most isolated germ (36%). 64% of patients had inflammatory anemia and 57% of patients had an inflammatory biological syndrome. Ultrasound and CT revealed obstruction of the urinary tract in all cases: a lithiasic cause in 90% of cases and the rest were isolated cases of retroperitoneal fibrosis, abnormal pyelo-ureteral junction, ureteral stenosis and pyelo-ureteric duplicity. A peri-renal abscess and / or psoas was associated in 6 cases (14%). The preoperative diagnosis was often pyonephrosis (50%). Neoplasia was suspected in 4 cases. The treatment consisted in a radical nephrectomy for all patients preceded by drainage of the excretory pathways in 41% of the cases and drainage of a collection in 21% of the cases. CONCLUSION: The XGPN is a rare entity whose diagnosis is difficult. This is suspected on a cluster of clinical and biological arguments and can be evoked on the preoperative CT. The kidney cancer is the main differential diagnosis.

Pyeloduodenal Fistula in Xanthogranulomatous Pyelonephritis: A Series of Two Cases.

Xanthogranulomatous inflammation, characterized by destruction and replacement of tissues with chronic inflammatory cells, including foamy histiocytes and hemosiderin-laden macrophages, is uncommon. In patients with xanthogranulomatous pyelonephritis, inflammation may extend from the kidney to the overlying duodenum, creating a pyeloduodenal fistula that further complicates medical and surgical management. We present two cases with recurrent kidney infections who each ultimately received a nephrectomy and repair of their duodenal fistula.

Primary Squamous Cell Carcinoma of Renal Pelvis in Non-Functioning Kidneys.

Primary renal pelvic squamous cell carcinomas comprise 0.5% of all renal neoplasms and are rare. The most common risk factor is nephrolithiasis. They are diagnosed late due to non-specific imaging and uncertain clinical features. With these two cases, we recommend periodic urine cytology and contrast imaging for chronic nephrolithiasis patients; and if suspected, fine needle aspiration cytology or tru-cut biopsy to be used in order to exclude malignancy that can develop on the basis of chronic pyelonephritis / nephrolithiasis.

[Renal tumor or pseudotumoral xanthogranulomatous pyelonephritis]. / Tumeur rénale ou pyélonéphrite xanthogranulomateuse pseudotumorale.

We here report the case of a 55 year-old man presenting with right renal colic and with a history of intermittent lower back disorders. At the time of admission, clinical examination showed lower back pain on contact. Renal ultrasound objectified heterogeneous mass at the lower pole of the right kidney with dilation of lower calyx groups. Abdominal CT scan confirmed the presence of right inferior renal polar lesion characterized by mixed density, associated with significant hydronephrosis eroding the renal parenchyma upstream of a voluminous pyelic coralliform lithiasis. The patient underwent nephrectomy with anatomo-pathological examination revealing chronic inflammation of the renal parenchyma characterized by macrophages associated with monocytes and lymphocytes with spongy cells and fibrosis. Anatomo-pathological result was compatible with a diagnosis of xanthogranulomatous pyelonephritis. Xanthogranulomatous pyelonephritis is a relatively rare chronic pyelonephritis whose symptoms resemble those of a pseudotumor. The diagnosis is suspected on the basis of clinical arguments and on laboratory tests and may be evoked quite exclusively on the basis of preoperative CT scan. Kidney cancer was its main differential diagnosis.

Extensive renal sinus lipomatosis in xanthogranulomatous pyelonephritis simulating liposarcoma

ABSTRACT Renal replacement lipomatosis is a condition characterized by varying degrees of renal parenchymal atrophy and perirenal fibrofatty proliferation secondary to chronic inflammation such as xanthogranulomatous pyelonephritis. In severe cases, imaging findings can be misdiagnosed as retroperitoneal liposarcoma.

Extensive renal sinus lipomatosis in xanthogranulomatous pyelonephritis simulating liposarcoma.

Renal replacement lipomatosis is a condition characterized by varying degrees of renal parenchymal atrophy and perirenal fibrofatty proliferation secondary to chronic inflammation such as xanthogranulomatous pyelonephritis. In severe cases, imaging findings can be misdiagnosed as retroperitoneal liposarcoma.

Xanthogranulomatous pyelonephritis in a paediatric cohort (1963-2016): Outcomes from a large single-center series.

BACKGROUND: Xanthogranulomatous pyelonephritis (XGP) is an uncommon chronic destructive granulomatous inflammation of the kidney. It was first described in 1916, and is thought to affect 6/1000 cases of pyelonephritis. Its manifestations are varied, and with a limited number of cases in the literature, the optimal diagnosis and management of XGP in the paediatric cohort is still unknown. MATERIAL AND METHODS: The medical records of children who were diagnosed and treated for XGP at the current unit during the period 1963-2016, inclusive, were retrospectively reviewed. Information pertaining to each patient was recorded, including: demographic data, past medical history, clinical and biochemical characteristics, diagnostic procedures, treatment methods, histopathologic diagnosis of the removed specimen, and outcome. RESULTS: A total of 66 children with a median age of 4.84 years (range 1.1-14.81), with an M:F ratio 1.35:1 underwent nephrectomy for XGP and had a median follow-up of 7.19 years (range 0.11-17.45). The most common presentations were systemic illness (62.1%), pain (60.6%), urinary tract infections (54.5%) and an abdominal mass (39.4%); pyrexia was present in 53%. Biochemical abnormalities included anaemia (86.3%), thrombocytosis (80.3%) and hypomagnesemia (65.1%). There was an 83.3% concordance between intraoperative cultures and positive mid-stream urines. Index kidneys were significantly larger than the contralateral side (mean 1.32 cm; P = 0.002). Staging of XGP demonstrated extension beyond the kidney in 79% of kidneys. Computed tomography (CT) was performed in 11 cases (Summary figure). Dimercaptosuccinic acid (DMSA) scan showed 0-10% function in 90.47% of cases. Surgical procedures included nephrectomy (n = 63) and partial nephrectomy (n = 3). Perioperative complications included colonic resections (n = 5) and abscess formation in 18%. CONCLUSIONS: This is the largest series to date of XGP in a paediatric cohort. XGP should be included in the differential diagnosis of all children presenting with perirenal or psoas abscesses, renal masses and/or non-functioning kidneys with/or without associated urolithiasis. Clinical awareness and a high index of suspicion is required to achieve the correct pre-operative diagnosis and appropriate management.

[Abdominal mass revealing xanthogranulomatous pyelonephritis in an infant]. / Masse abdominale chez un nourrisson révélant une pyélonéphrite xanthogranulomateuse.

Xanthogranulomatous pyelonephritis (XGP) is a chronic pyelonephritis observed in children and exceptionally in infants. Symptomatology is vague and may delay diagnosis and patient's management. Treatment is based on medical therapy but most often on surgery with poor renal prognosis. We report the case of a 15-month old infant with isolated mass in the left flank. He had no fever or alteration of general state and urine cultures were sterile. Radiological evaluation (renal ultrasound, uroscan and renal scintigraphy) highlighted left non-functioning kidney with "hydropyonephrosis" evoking the diagnosis of XGP. The indication for total nephrectomy by lombotomy was posed and definitive anatomo-pathological examination confirmed the diagnosis of diffuse XGP. This observation emphasizes the importance of suspect PXG in patients with renal mass or malformative uropathy with recurrent urinary tract infections whose treatment should be rigorous and codified.