Xanthogranulomatous pyelonephritis--the "great imitator" justifies its name

Clinicopathological Spectrum of Xanthogranulomatous Pyelonephritis

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

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.

Xantogranulomatous pyelonephritis: The missed diagnosis

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Xantogranulomatous pyelonephritis (XGPN) is a rare chronic inflammatory disease of the kidney.

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The focal form imitates greatly renal cell carcinoma (RCC).

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We report a challenging clinical case of a 38-year old with lack of history of stone disease or urinary tract infection.

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Preoperative diagnosis of focal XGPN was difficult because of radiological similarities to RCC.

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An open right radical nephrectomy including the adrenal in the resection was performed and final histology revealed a focal renal mass which consist with a xantogranulomatous pyelonephritis.

Introduction

Xantogranulomatous pyelonephritis (XGPN) is a rare chronic inflammatory disease of the kidney that can be focal or diffuse with the focal form imitating greatly renal cell carcinoma (RCC).

Presentation of case

We report a challenging clinical case of a 38-year old male with right flank pain persisting for 3-months, imaging showed an 8 cm heterogenous mass of the upper pole of the right kidney and invading the liver. A right radical nephrectomy including the adrenal in the resection was performed under the tentative diagnosis of renal cell carcinoma (RCC) whereas histology revealed focal XGPN.

Discussion

Preoperative diagnosis of focal XGPN was difficult because of radiological similarities to RCC and lack of history of stone disease or urinary tract infection.

Conclusion

This case highlights the need to include XGPN in the differential diagnosis of RCC even in the era of modern imaging.

Xanthogranulomatous pyelonephritis mimicking a renal cell carcinoma: a unique and challenging case

We describe an unusual case of xanthogranulomatous pyelonephritis (XGPN) in a 73-year-old woman diagnosed after a blunt abdominal trauma. This case is unique because of the atypical presentation, with absence of symptoms, normal laboratory exams, and unusual computed tomography and magnetic resonance imaging findings. The patient underwent radical nephrectomy because a renal cystic tumor was suspected. Only the histopathological findings suggested the final diagnosis of XGPN.

Xanthogranulomatous pyelonephritis (XGPN) mimicking a "renal cell carcinoma with renal vein thrombus and paracaval lymphadenopathy"

We present a case of Xanthogranulomatous pyelonephritis mimicking as a renal cell carcinoma. This was an elderly lady who presented with pyonephrosis due to urolithiasis. On evaluation she was found to have a space occupying mass in the right kidney. Further investigations revealed an enhancing tumor with renal vein thrombus and paracaval lymphadenopathy. Subsequent histopathology showed evidence of XGPN with no malignancy. This case report highlights the fact there are a number of imaging and clinical overlaps in the diagnosis, assessment and management of this entity.

Pyelonephritis xanthogranulomatosa in a 7-year-old girl

Xanthogranulomatous pyelonephritis (XGPN) is rare form of chronic, usually unilateral, renal infection that involves damage to the renal glomeruli and periglomerular tissue and destruction of the renal parenchyma.

Nephrectomy is usually necessary and the prognosis is good if XGPN is unilateral and treated early. XGPN typically affects middle-aged females and is extremely rare in children. We report one case of XGPN in a seven-year-old girl who was operated on at our institution be-cause of lower urinary tract dysfunction and renal insufficiency – the left kidney was removed and the bladder was augmented by means of the remaining ureter. The histopathological evaluation of the removed kidney showed chronic XGPN.

[Imaging features of xanthogranulomatous pyelonephritis]

Pseudotumoral xanthogranulomatous pyelonephritis is a rare chronic renal infection. Preoperative diagnosis is difficult because of its non-specific presentation. The purpose of this retrospective review of 8 cases is to assess the value of different imaging techniques in the evaluation of this pathology. Six males and 2 females, aged 29 to 75 years were included. The right kidney was involved in 5 cases and the left kidney was involved in 3 cases. Involvement was upper polar in 2 cases and lower polar in 6 cases. A kidney stone was present in 3 cases. US showed a heterogeneous hypoechoic lesion in 3 cases, a homogeneous hypoechoic lesion in 3 cases, and isoechoic lesion in 1 case and a cystic lesion in 1 case. CT showed a focal solid lesion with peripheral enhancement in 4 cases and a cystic mass with peripheral enhancement in 3 cases. US features are non-specific. CT shows a non-specific renal mass, the presence of obstruction and demonstrates perirenal involvement. Preoperative MRI, not performed in our patient population, demonstrates specific changes in the perirenal fat that suggests the diagnosis. The diagnosis of pseudotumoral xanthogranulomatous pyelonephritis can be suspected on a constellation of clinical and laboratory findings combined with non-specific features on CT and US and specific MRI features of perirenal fat changes. Percutaneous biopsy may be needed in selected cases to confirm diagnosis.

Xanthogranulomatous orchitis: Review of the published work and report of one case

Xanthogranulomatous orchitis is an extremely rare inflammatory non-neoplastic destructive lesion of the testis. We report a 44-year-old man who presented with right scrotal swelling and two discharging sinuses. Testicular tumor markers were normal. Scrotal ultrasound showed heterogeneous testicular areas and irregular margin of the tunica. Surgical exploration revealed infected, unhealthy testicular tissue with necrosis and tumor-like lesion. Orchidectomy was done and histopathology showed xanthogranulomatous orchitis.

Feasibility of laparoscopic approach in management of xanthogranulomatous pyelonephritis

OBJECTIVES

To report the feasibility of the laparoscopic approach for management of xanthogranulomatous pyelonephritis (XGP).

METHODS

From 2002 to 2005, 11 patients underwent laparoscopic (n = 7) or hand-assisted laparoscopic (n = 4) nephrectomy by a single surgeon for pathologically confirmed XGP. The preoperative presentation, operative details, postoperative recovery, and complications were recorded.

RESULTS

A total of 5 men and 6 women were included in this study, and the mean patient age was 51 years (range 28 to 78). All cases began with the laparoscopic approach (6 left and 5 right). Four cases were converted to the hand-assisted technique because of the difficulty in progression, but no case required conversion to open nephrectomy. The mean operative time was 157 minutes (range 101 to 201), with a mean estimated blood loss of 217 mL (range 50 to 440). No intraoperative complications occurred. The mean hospital duration was 2.4 days (range 1.5 to 4). Four patients had postoperative complications, including two with an ileus, one with a persistent fever requiring intravenous antibiotics, and one with a renal fossa abscess requiring percutaneous drainage. All specimens were pathologically confirmed to be XGP.

CONCLUSIONS

Laparoscopic nephrectomy for XGP is complicated and more technically demanding than the laparoscopic nephrectomy for noninfectious etiologies. Consideration should be made for using a hand port should the laparoscopic procedure fail to progress in a satisfactory manner. In experienced hands, the laparoscopic approach presents a reasonable surgical option for the treatment of XGP. For the novice laparoscopist, however, the open approach should remain the modality of choice.

Xanthogranulomatous Pyelonephritis: Analysis of 18 Cases

OBJECTIVE

To review and evaluate patients with a clinicopathological diagnosis of xanthogranulomatous pyelonephritis (XGP) with emphasis on the diagnostic methods and the effect of socioeconomic status on disease severity.

METHODS

Data compiled from the previous history of the patients, clinical, laboratory, radioimaging findings, preoperative, operative, histopathological diagnosis and postoperative follow-up period were analysed. On the basis of presentation, XGP was classified as complicated and simple.

RESULTS

There were 18 cases of XGP. The clinical characteristics included: calculi or obstruction in the urinary tract, and damage to the kidney, complication of urinary tract infection, anaemia, increased erythrocyte sedimentation rate and liver dysfunction. All patients had diffuse XGP. Associated pathological findings such as psoas abscess, nephrocutaneous fistula, renocolonic fistula and paranephric abscess were found in 33.3% of cases. Eleven of 14 patients (78.6%) who were evaluated by computed tomography (CT) had the correct diagnosis made prior to nephrectomy. Urine culture was positive in 88.9% of patients and Proteus mirabilis was the most common organism.

CONCLUSION

Our experience with a small number of patients demonstrates that low socioeconomic status could be a risk factor in the development of complicated cases of XGP. CT is considered to be the best radiological test for correct preoperative diagnosis and evaluation of XGP. Nephrectomy and removal of all surrounding affected tissue proved to be curative for XGP.

Xanthogranulomatous funiculitis and orchiepididymitis: report of 2 cases with immunohistochemical study and literature review

Two patients with xanthogranulomatous inflammation are described, one with involvement of the spermatic cord and the other with 1 testicle and epididymis affected. To our knowledge, only 12 cases of xanthogranulomatous orchiepididymitis have been reported previously, one of which also presented a xanthogranulomatous funiculitis. Clinically, our patients presented with spermatic cord enlargement (case 1) and chronic orchitis that did not respond to treatment with antibiotics (case 2). Histopathologically, both cases showed extensive xanthogranulomatous inflammation with numerous foamy macrophages that were associated with colonies of microorganisms suggestive of actinomyces in case 1. Additionally, Escherichia coli was cultured from the surgical specimen of case 2. The possible underlying pathology may be diabetes in case 1 and phlebitis associated with chronic orchitis in case 2. Differential diagnoses with other lesions that are rich in macrophages, such as malakoplakia, and those testicular neoplasms without serologic tumor markers are discussed.

Ultrasonographic features of focal xanthogranulomatous pyelonephritis

OBJECTIVE

To analyze the ultrasonographic features of focal xanthogranulomatous pyelonephritis.

METHODS

Ultrasonographic features of 15 patients with pathologically proved focal xanthogranulomatous pyelonephritis were retrospectively analyzed by 2 radiologists who reached a consensus, in terms of the location, margin, size, and echo texture of the mass, associated calculi, lymphadenopathy, or local extension, in comparison with computed tomographic and clinical findings.

RESULTS

At ultrasonography, 12 (80%) of 15 masses were well circumscribed. The maximal sizes of the masses ranged from 2.5 to 5.8 (mean, 3.8) cm. Thirteen solid masses (87%) were hyperechoic (n = 7), hypoechoic (n = 4), or isoechoic (n = 4) to the renal cortex, and the preoperative diagnosis was either renal cell carcinoma (n = 11) or Wilms tumor (n = 2). The preoperative diagnosis of the other 2 cystic lesions (13%) was renal abscess. Renal calculi were found in 1 case, but lymphadenopathy or local extension was not depicted. Clinical inflammatory signs were found in 11 of 15 patients.

CONCLUSIONS

There were no specific ultrasonographic features that allow for the distinction between focal xanthogranulomatous pyelonephritis and renal tumors or abscesses. Focal xanthogranulomatous pyelonephritis should be considered when there are clinical signs of infection or inflammation and a focal solid mass is seen on ultrasonography.