Pielonefritis xantogranulomatosa: conceptos actuales en el diagnóstico y tratamiento / Xanthogranulomatous pyelonephritis: current concepts of diagnosis and treatment

Introducción: La Pielonefritis Xantogranulomatosa (PNF XG) es una patología de baja prevalencia, frecuentemente asociada a litiasis y destrucción del parénquima renal. Dada la gran masificación de la tomografía axial computada su diagnóstico y manejo es cada vez más precoz disminuyendo así la morbi-mortalidad perioperatoria. Objetivos: Describir la experiencia de nuestro servicio en PNF XG y realizar un análisis de la literatura sobre los conceptos actuales en el diagnóstico y tratamiento de esta patología. Materiales y métodos: Análisis retrospectivo de todas la nefrectomías totales realizadas en nuestro servicio entre los años 2000 y 2007. Se incluyeron sólo las piezas con el diagnóstico histológico de PNF XG. Resultados: Se encontraron 11 casos con el diagnóstico histológico de PNF XG. La edad promedio de presentación fue de 54 años con una leve tendencia al sexo femenino. En todos los pacientes se encontró una historia actual o reciente de litiasis urinaria. En todos los casos se realizó un estudio imagenológico preoperatorio, siendo 9 de ellos estudiados con TAC de abdomen y encontrándose la presencia de litiasis en 7 pacientes. Todos los pacientes fueron manejados mediante una nefrectomía total por lumbotomía, sin registrarse mortalidad. Conclusiones: La PNF XG constituye un desafío en sí misma. A pesar de ser una patología rara y de difícil diagnóstico, una cuidadosa evaluación preoperatoria y alto índice de sospecha, pueden ayudarnos a realizar un diagnóstico oportuno y realizar el manejo más adecuado, disminuyendo así las complicaciones perioperatorias.

Introduction: Xanthogranulomatous pyelonephritis (XG PNF) is a low prevalence disease, often associated with lithiasis and renal parenchymal destruction. The wide availability of tomographic (CT) diagnosis allows for frequent early management decreasing perioperative morbidity and mortality. We describe the experience at our institution in XG PNF and perform an analysis of the literature onthe current concepts in diagnosis and treatment of this condition. Materials and methods: Retrospective analysis of all nephrectomies performed at our department between 2000 and 2007. Only surgical specimens with histological diagnosis of XG PNF were included. Results: We found 11 cases with histologic diagnosis of XG PNF. Average age of presentation was 54 years with a slight tendency towards females. All patients had a current or recent history of urolithiasis. In all cases a preoperative imaging study was made, 9 of them were studied with abdominal CT scan and found the presence of stones in 7 patients. All patients were treated by an open total nephrectomy without mortality. Conclusions: The XG PNF is a challenge in itself. Despite being infrequent and difficult to diagnosis, a careful preoperative evaluation and a high index of suspicion can help to make an early diagnosis and management, thus reducing perioperative complications.

Which are Risk Factors developing Renal Cortical Defects on 99 mTc - DMSA Scintigraphy in Children with Acute Urinary Tract Infections?

PURPOSE: To determine (1) the relationship between the cortical defects seen on 99 mTc-DMSA renal scans and age, and (2) the presence and degree of vesicoureteral reflux, and then to depict the risk factors for cortical defects in children with acute urinary tract infection (UTI). Furthermore, to assess the diagnostic value of VCUG in predicting a defect on 99 mTc-DMSA renal scans. MATERIALS AND METHODS: We studied 134 kidneys in 67 children aged 15 days-10 years (M:F=39:28) in whom symptomatic UTI was present. In all these children, both DMSA renal scans and voiding cystourethrography (VCUG) were performed. Scanning took place within 7 days of diagnosis and VCUG was performed after one month of diagnosis. Scintigraphic findings were graded according to the extent and number of cortical defects. We evaluated the relationships between the cortical defects seen on DMSA scans and age, and the grade of vesicoureteral reflux. The diagnostic value of VCUG in predicting cortical defects was analysed. Results: The prevalence of cortical defects was greater in patients older than two years (38/54, 70%) than in those aged less than two (38/80, 48%). The frequency of cortical defects was related to vesicoureteral reflux (p or =2yrs) at the time of acute UTI, and high grade of vesicoureteral reflux. The specificity of VCUG in predicting cortical defects is relatively high but the sensitivitiy is low, and a significant proportion of cortical defects therefore occurred in the absence of vesicoureteral reflux.

CT of Acute Pyelonephritis in Children: Comparison with Tc-99m DMSA Scintigraphy

PURPOSE: The purpose of the study was to compare CT with scintigraphy in the detection of parenchymal lesionsof acute pyelonephritis in children, and to assess the diagnostic value of CT. MATERIALS AND METHODS: This studyinvolved 32 children with acute pyelonephritis ; their ages ranged from 1 month to 10 years. Renal CT , TC-99mDMSA planar and SPECT images, and medical records were retrospectively reviewed. We evaluated the number, size,shape, density, and location of pyelonephritic lesions, as seen on CT and scintigraphic images. RESULTS: In 43involved kidneys, 193 parenchymal lesions of acute pyelonephritis were identified. The results of CT were abnormalin 42 kidneys (98%), and those of scintigraphy, in 39(91%). CT showed single or multiple hypoenhancing parenchymallesions ; these were streaky(n=151), wedge-shaped (n=34), or oval (n=8), and ranged from about 3-30mm in maximumdiameter. Abscess (n=5), renal fascial thickening (n=6) and thickening of the bridging septae (n=7) wereassociated. Scintigraphic findings were diffuse or localized area of varying degrees of diminished corticalactivity, and these were more precisely identified on SPECT than on planar images. For the detection of 55 of 193pyelonephritic lesions, CT was more sensitive than scintigraphy ; 29 of the 55 lesions were less than 5 mm indiameter. CONCLUSION: For the detection of pyelonephritic lesions, particularly smaller ones, and for theevaluation of complications such as abscess formation, CT is more sensitive than Tc-99m DMSA scintigraphy. Weconclude that in children with subtle scintigraphic findings who are in serious clinical condition or in whomcomplications are suspected, CT is a useful tool for assessing a therapeautic plan and the prognosis of acutepyelonephritis.

Nontraumatic Spontaneous Rupture of the Kidney: Etiology and CT Findings

PURPOSE: To evaluate the usefulness of CT scanning in determining the etiology of spontaneous rupture of the kidney. MATERIALS AND METHODS: We retrospectively analyzed the CT findings of spontaneous rupture of the kidney in eleven patients, Four were male and seven were female, and they were aged between 20 and 71 (mean, 46.6) years. Both pre- and post-contrast enhanced CT scanning was performed in all patients. RESULTS: Spontaneous renal rupture was induced in seven cases by neoplasms (three angiomyolipomas, three renal cell carcinomas, and one metastatic choriocarcinoma), in three cases by infection or inflammation (acute and chronic pyelonephritis, and renal abscess), and in one, by renal cyst. Common CT findings of rupture of the kidney were the accumulation of high density fluid in the perirenal and anterior pararenal space, and in homogeneous irregular low density of renal parenchyma and the rupture site. Angoimyolipoma showed fat and an angiomatous component in the lesion, while acute and chronic pyelonephrities revealed thinning of the renal parenchyma and an irregular renal outline. Renal cell carcinoma showed a dense soft tissue mass in the parenchyma. Well-defined, round low-density lesions were noted in the case of renal cyst and renal abscess. CONCLUSION: CT is very useful in diagnosing and determining the etiology of non-traumatic spontaneous rupture of the kidney and plays an important role in the evaluation of emergency cases.

Percutaneous Drainage of Abscess in the Treatment of Emphysematous Pyelonephritis

PURPOSE: To assess the usefulness of percutaneous drainage of abscess in the treatment of emphysematous pyelonephritis. MATERIALS AND METHODS: Ten cases of nine patients with emphysematous pyelonephritis were percutaneously drained. All were suffering from diabetes mellitus. The procedure was performed under fluoroscopic guidance in nine cases and US guidance in one case in which bilateral multiloculated abscesses were present in the perirenal spaces. The results were classified as cure, partial success, recurrence, or failure. The mean drainage period and complication were analyzed. RESULTS: Eight cases were cured, and there was one partial success. In one case, who had diffuse renal parenchymal destruction without perirenal fluid collection, the treatment failed. The longest drainage period was 45 days, in a case of re-insertion due to incidental catheter removal ; the mean was 23 days. Bacteremia in one case was cured with antibiotic therapy which lasted two days. CONCLUSION: In diabetic patients, percutaneous drainage of abscess is thought to be a safe and effective method for the treatment of emphysematous pyelonephritis, and is one that does not involve diffuse destruction of renal parenchyma.

Focal Xanthogranulomatous Pyelonephritis: Reports of 2 Cases

Xanthogranulomatous pyelonephritis is a chronic inflammatory condition which in most cases involves either an entire non-duplicated kidney or a moiety of a duplicated kidney. These cases present with quite characteristic radiologic findings including an enlarged non functioning kidney and renal stones. However, when the condition involves only a part of a non-duplicated kidney and especially where there is an absence of the specific findings described above, differentiation from cystic neoplasm may be difficult. We report the radiologic findings of twosuch cases of focal xanthogranulomatous pyelonephritis.