Xanthogranulomatous pyelonephritis

Complicated pyelonephritis associated with chronic renal stone disease

Purpose

This article reviews imaging manifestations of complicated pyelonephritis associated with chronic renal stones disease, in particular xanthogranulomatous pyelonephritis (XGP) and emphysematous pyelonephritis (EPN), as potential mimics of other renal diseases and malignances and provides helpful tips and differentiating features that may alert the radiologist to suspect a diagnosis of infection.

Materials and methods

A retrospective review of the records from 6 adult patients (5 females and 1 male, mean age 72,3 years) with diagnosis of XGP associated with chronic nephrolithiasis and 7 adult patients (6 females and 1 male, mean age 59,3 years) with diagnosis of EPN associated with chronic nephrolithiasis from January 2010 to January 2020 was carried out. Computed tomography urography (CTU) with at least an unenhanced scan, and the parenchymal and excretory phases after contrast medium administration performed at our Teaching Hospital were included. When available images related to conventional radiography, ultrasound (US) and magnetic resonance imaging of the same patients, the comparison with CTU images was carried out.

Conclusion

A possible diagnosis of XGP or EPN must always be taken into account when a pyelonephritis is associated with untreated kidney stones, especially whenever clinical presentation is atypical, current therapy is not effective and imaging shows features of dubious interpretation. Due to their rarity and atypical presentation, a multidisciplinary approach is required and an expert radiologist represents a key figure in the multidisciplinary team as he can help to differentiate between benign and malignant lesions and thus avoid unnecessary radical surgical procedures.

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis is a rare chronic form of pyelonephritis with a clinical presentation often suggestive of a renal mass. We present 51 patients with histologically proven xanthogranulomatous pyelonephritis who were treated by nephrectomy. The results are discussed and compared with those from the literature.

Xanthogranulomatous pyelonephritis

Four patients with xanthogranulomatous pyelonephritis are presented; all patients were male and their symptoms were not urinary but nonspecific. Three of the patients are from a low socioeconomic class and did not have adequate medical services; therefore, we suggest that the disease is underreported.

Xanthogranulomatous pyelonephritis in bilharzial patients: a report of 25 cases

The preoperative diagnosis of xanthogranulomatous pyelonephritis is difficult due to its similarities to other renal diseases. Also, its relationship to bilharziasis to the best of our knowledge has never been studied. We attempted to explore these 2 problems by reviewing the files and pathological slides of 25 patients whose diagnosis was proved histopathologically to be xanthogranulomatous pyelonephritis. We concluded that the diagnosis of xanthogranulomatous pyelonephritis preoperatively still is difficult. We believe that bilharziasis is an etiologic factor for the disease by increasing the incidence of urinary tract obstruction, infection and stone formation. We plan to study this relationship further by examining the freshly removed kidneys immunohistologically.

Development of fatal bilateral xanthogranulomatous pyelonephritis in a paraplegic patient: case report

The first case of a bilateral xanthogranulomatous pyelonephritis (XGPN) is reported in a paraplegic patient who did not practise intermittent catheterisation after discharge from the hospital but resorted to the Crede manoeuvre which predisposed to a fatal urinary tract infection and development of XGPN over a period of 5 weeks. The advantages of clean, unsterile, intermittent self catheterisation over the Crede manoeuvre in patients with a neuropathic bladder are discussed especially in preventing infective complications of the upper urinary tract which may prove life threatening as occurred in this patient.

Xanthogranulomatous pyelonephritis with emphasis on computerized tomography scan. Retrospective study of 20 cases and literature review

The authors reviewed 20 cases of xanthogranulomatous pyelonephritis. An accurate preoperative diagnosis of this disease is difficult because of its clinical and radiologic similarities to various other renal lesions. A resistant urinary tract infection in a patient with a nonfunctioning kidney and a perinephric abscess should lead to the condition being suspected. Although xanthogranulomatous pyelonephritis is mainly a histologic diagnosis, computerized tomography opens new perspectives in the preoperative determination. This could allow less radical surgery in selected cases.

Fistula and sinus formation in xanthogranulomatous pyelonephritis. A clinicopathological review and report of four cases

Fistula or deep sinus formation as a complication of xanthogranulomatous pyelonephritis (XPN) has not been described previously in the British literature. We present the clinicopathological features of one case of a nephrodiaphragmatic sinus complicating XPN, and three cases of nephrocolic fistula, including the first recorded case of fistula in childhood XPN. The detailed clinical, radiological and pathological features of XPN and its complications are reviewed. Total nephrectomy, together with primary excision of sinuses or fistulae, is the treatment of choice.

Xanthogranulomatous pyelonephritis caused by methicillin-resistant Staphylococcus aureus

Localized xanthogranulomatous pyelonephritis due to methicillin-resistant Staphylococcus aureus developed in a 41-year-old diabetic patient. She had recurrent bacteremia despite appropriate therapy with vancomycin. Nephrectomy was required for cure and clinical diagnosis. This report emphasizes differences in the clinical presentation and pathogenesis of xanthogranulomatous pyelonephritis caused by S. aureus. Compared with the common form of xanthogranulomatous pyelonephritis caused by gram-negative bacilli, the localized disease due to S. aureus probably results from hematogenous seeding and is not associated with nephrolithiasis or ureteral obstruction. Furthermore, this report indicates that xanthogranulomatous pyelonephritis may be caused by methicillin-resistant S. aureus, a rapidly emerging nosocomial pathogen.

Preoperative diagnosis of renal xanthogranulomatosis by serial urinary cytology: preliminary report

The search for foam cells in the urinary sediment of patients with possible renal xanthogranulomatosis can constitute a harmless and useful diagnostic method for this frequently occurring renal disease, which previously has been diagnosed with certainty only by histological examination or biopsy. Of 5 cases studied the search was positive in 80 per cent.

Xanthogranulomatous pyelonephritis

Evaluation of clinical, radiological and pathological data from 10 adult patients with xanthogranulomatous pyelonephritis has been carried out. There are no pathognomonic diagnostic features, but the majority of patients present with a previous history of recurrent urinary tract disorders. Obstruction and infection are essential pathogenetic factors, but it is suggested that immunologic factors are also play a part. The treatment is nephrectomy, as correct diagnosis cannot be established preoperatively, and as the condition is often misinterpreted as renal carcinoma. A definite diagnosis can only be obtained from pathologic examination with demonstration of the characteristic inflammatory xanthogranulomatous reaction.

Xanthogranulomatous pyelonephritis: a critical analysis of 26 cases and of the literature

Manifestations of xanthogranulomatous pyelonephritis in 26 patients closely mimicked those of neoplastic and other inflammatory renal parenchymal diseases. Middle-aged or older women were affected most often. Most patients presented with anemia, chronic febrile illness, a painful tender flank mass and recurrent urosepsis. Some features of nephrogenic hepatic dysfunction were present in 13 patients. Bacterial cultures of renal tissue were almost always positive but the spectrum differed considerably from that of the bladder urine. Urographically, a renal mass lesion was encountered in 62% of the patients, nephrolithiasis in 38% and a functionless kidney in 27%. Angiographically, none of the 4 mass lesions studied was distinguished from hypernephroma. Indeed, a correct preoperative diagnosis was made in only 1 instance. There were 3 stages of xanthogranulomatous pyelonephritis recognized. Treatment consisted of nephrectomy for diffuse or advanced stage disease or both (21 patients), excision of the diseased renal segment for localized and low stage disease (2 patients) and renal biopsy (3 patients). Xanthogranulomatous pyelonephritis did not recur but in some patients bacteriuria continued or hypertension developed.

Xanthogranulomatous pyelonephritis masquerading as occult malignancy

Xanthogranulomatous pyelonephritis (XGP) can present with weight loss, anemia, leukemoid reaction, and generalized debility; there may be no signs or symptoms referable to the urinary tract. Confusion between XGP and renal adenocarcinoma is well recognized, but other malignancies can also be simulated. Case histories of patients with proved XGP whose clinical presentations suggested occult malignancies are recorded. Proteus urinary tract infection, calculi, and a nonvisualizing kidney on intravenous pyelogram should suggest the correct diagnosis. The pathology, bacteriology, diagnosis, and treatment are reviewed.

Xanthogranulomatous pyelonephritis. A comparison of the disease in the cat and man with special reference to the origin of the fat

The origin of the intracellular fat in human xanthogranulomatous pyelonephritis has been the centre of some discussion in the past. A report of a case in a domestic cat is of interest as normal feline renal epithelium is rich in stainable fat. A comparison of the human and feline varieties of xanthogranulomatous pyelonephritis reveals certain fundamental differences between the two and reinforces the view that the fat concerned in the human disease does not originate in the renal epithelium.

A case of xanthogranulomatous pyelonephritis

A patient with a non-functioning kidney was investigated. Although the arteriographic findings suggested an inflammatory process, a malignant lesion could not be excluded. The appearance of the kidney at operation suggested malignancy but histological examination following nephro-ureterectomy showed xanthogranulomatous pyelonephritis. This is an uncommon reaction to severe renal infection and is often associated with upper renal tract obstruction. The clinical and radiological findings of this condition are reviewed.