Sonographic features of xanthogranulomatous pyelonephritis

Abstract

ABSTRACT:Purpose. The purpose of this study was to describe the various sonographic features of xanthogranulomatous pyelonephritis (XGP).Methods. We retrospectively reviewed the CT, sonographic, and medical records of patients diagnosed with XGP from January 1981 to December 1998. Twenty-seven patients for whom XGP was histopathologically confirmed were included in the study. There were 12 men and 15 women, with an age range of 21-86 years (mean, 57 years). All patients had undergone sonography of the kidneys. The renal size, shape, and outline were recorded. The presence of perinephric fluid accumulation, of obstructive uropathy, or of internal echoes in the dilated collecting system and the echotexture of the renal parenchyma were documented.Results. We categorized the XGP into 4 groups on the basis of the sonographic features: (1) diffuse hydronephrotic, 12 patients (44%); (2) diffuse parenchymal, 9 patients (33%); (3) diffuse contracted, 4 patients (15%); and (4) segmental or focal, 2 patients (7%). A localized perinephric fluid collection was present in 4 patients (15%). The preoperative sonographic diagnoses were pyonephrosis (n = 14, 52%), renal pelvic tumor with possible associated infection (n = 5, 19%), renal parenchymal mass (n = 2, 7%), hydronephrosis (n = 2, 7%), and chronic pyelonephritis with renal atrophy (n = 4, 15%). XGP was considered a possible diagnosis in only 11 patients (41%).Conclusions. XGP has no specific sonographic features but is suggested by parenchymal thinning and hydronephrosis, sonographic signs of chronic obstructive uropathy caused by stones; echoes in the dilated collecting system; and a perinephric fluid collection. CT, needle biopsy, or both are recommended to further evaluate and confirm sonographically suspected XGP.

Xanthogranulomatous pyelonephritis: critical analysis of 30 patients

“…The US pattern of XGP is described in several reports [28][29][30]. In Kim's report, US not only helped to differentiate focal from diffuse XGP but identified calcifications, complicated cystic lesions, hydronephrosis, shadows of renal stones, and a solid mass with inhomogeneous echogenicity [30].…”

Xanthogranulomatous pyelonephritis treated by partial nephrectomy

“…Thus, Tc-99m DMSA renal SPECT can assist in detecting a renal mass and can estimate individual renal function in young infants. The typical ultrasonography findings of the diffuse form include increased renal size, replacement of the normal parenchyma with multiple fluid-filled masses, and a posterior acoustic shadow due to a renal stone [9,10]. In the focal form, hypoechoic areas due to distended calyces and an inflammatory mass, with a central hyperechoic area consisting of granulomatous tissue are noted.…”

Ultrasonographic Features of Focal Xanthogranulomatous Pyelonephritis

“…The disease is usually unilateral, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] as in all our cases. Two forms of XGP have been described: a focal (localized, segmental, tumefactive) form (15%) and a diffuse form (85%).…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Other suggested interrelated etiologic features are infection, ineffectively treated urosepsis, chronic renal ischemia causing localized alterations in renal metabolism, lymphatic obstruction, alterations in lipid metabolism, altered immune response, malnutrition, and congenital urinary anomalies, most commonly a duplex kidney. 3,12 In addition to the most common symptoms of flank pain and fever, other symptoms such as fatigue, weight loss, dysuria, and a tender flank mass may be present, with laboratory data of leukocytosis, anemia, and an increased ESR.…”

“…At the time of diagnoses, urine culture results are mostly positive, and the most common pathogens are E coli, P mirabilis, Staphylococcus aureus, Klebsiella, and Pseudomonas. [1][2][3][4][5][6][7][8][9][10][11][12] Of the 15 patients in our study, which included 3 patients from a previous report, 7 combinations of flank pain, fever, leukocytosis, or anemia were found in 11 patients, and urine culture results were positive (E coli and P mirabilis) in 5.…”