Interstitial Cells of Cajal and P2X3 Receptors at Ureteropelvic Junction Obstruction and Their Relationship with Pain Response.

Introduction: Etiopathogenesis and the symptomatology of ureteropelvic junction obstruction (UPJO) in the pediatric population has not yet been definitely clarified, suggesting a multifactorial nature of the condition. The aim was to analyze the association between the number of Interstitial Cells of Cajal (ICCs), as well as P2X3 receptors in ureteropelvic junction (UPJ) and the pain response in pediatric patients with hydronephrosis. Methods: 50 patients with congenital hydronephrosis underwent open or laparoscopic pyeloplasty at one of two departments of pediatric surgery and urology in Poland. Patients were divided into two groups according to the pain symptoms before surgery. A total of 50 samples of UPJ were obtained intraoperatively and underwent histopathological and immunohistochemical (IHC) analysis. Quantitative assessment of ICCs was based on the number of CD117(+) cells of adequate morphology in the subepithelial layer and the muscularis propria. Expression of P2X3 receptors was evaluated as the intensity of IHC staining. Results: Patients with hydronephrosis and accompanying pain were on average 60 months older (77 vs. 17 months) than children with asymptomatic hydronephrosis (p = 0.017). Symptomatic children revealed higher numbers of ICCs in both the subepithelial layer and in the lamina muscularis propria. In particular, symptomatic patients aged 2 years or more exhibited significantly higher numbers of ICCs in the subepithelial layer. Significant differences in the distribution of ICCs between the subepithelial layer and the lamina muscularis propria were observed in both groups. Expression of P2X3 receptors was limited to the urothelium and the muscle layer and correlated between these structures. There was no relationship between pain response and the expression of P2X3 receptors. Conclusions: ICCs and P2X3 receptors may participate in the pathogenesis of UPJO and in the modulation of pain response to a dilatation of the pyelocaliceal system. Explanation of the role of ICCs and P2X3 receptors in propagation of ureteral peristaltic wave and the modulation of pain stimuli requires further studies.

Preserved Voluntary Micturition Control despite Early Urinary Diversion in Infancy-A Clue to a New Strategy.

Micturition is an involuntary process based on spinal arcs in infants and children until a defined age. The awareness and voluntary control of voiding depends on specific areas in the central nervous system, especially cortical regions. The cells and connections between these areas develop over time and regulate the voiding process. The ability to maintain continence and to adjust physiological needs to appropriate environmental conditions is considered to be acquired through systematic behavioral education, especially toilet training. The recommendations specify the age at which to start establishing the relevant habits. The purpose of these guidelines is to achieve proper micturition control development and to avoid functional lower urinary tract (LUT) disorders. We present a case of a patient who underwent complete urinary diversion in infancy and reconstruction of the urinary tract eleven years later. For eleven years, she had an empty bladder and no toilet training. After undiversion, she regained full continence in a short space of time. The presence of proper LUT function and a controlled micturition process raises the question of the standard toilet training recommendations' validity. The aim of our work focuses on the following question: Is toilet training the only way to achieve micturition skills and proper urinary tract function? The history of our patient and the literature reveal that voluntary micturition may develop without stimulating signals of filling from bladder receptors and independently of recommended behavioral education, so toilet training seems to not be necessary.

Laparoscopic versus open pyeloplasty in children: experience of 226 cases at one centre.

INTRODUCTION: The aim of the study was to compare the efficacy of laparoscopic versus open dismembered pyeloplasty in children. MATERIAL AND METHODS: Two hundred and twenty-six Anderson-Hynes pyeloplasties were performed, out of which 131 by open access (OP) and 95 by laparoscopic access (LP). Retrospective analysis of data was performed. The median follow-up was 3 years for LP patients and 6 years for OP patients (p < 0.05). RESULTS: Success was achieved in 87 (91.57%) patients who had LP surgeries and in 121 (91.7%) patients who had OP (p > 0.05). Eight patients in the LP group and nine in the OP group required another surgery because of recurrent UPJO, and one patient in the OP group required a nephrectomy. The median operating time was 125 min (range: 70-225) for LP surgeries and 90 (40-200) for OP surgeries (p < 0.05). In the last 30 LP procedures, operation time decreased to a median of 95 min. Improvement in ultrasound analysis of the kidney was achieved in 89.06% of patients who had LP and 82.35% of patients who had OP. A stable or better function of the kidney in diuretic renography was achieved in 87.5% of patients in the LP group and 96.15% of patients in the OP group. CONCLUSIONS: Laparoscopic and open pyeloplasty is a highly efficient procedure employed to treat UPJO in children with comparable success rates in both groups. In experienced hands, it is possible to reduce the LP operation time to that comparable to the OP group.

Hydronephrosis in Children Caused by Lower Pole Crossing Vessels-How to Choose the Proper Method of Treatment?

Objectives: Assessment of the efficacy of intraoperative diagnosis between extrinsic and intrinsic UPJO in children. Assessment of the efficacy of laparoscopic vascular-hitch procedure in UPJO caused by lower pole crossing vessels (CV). Materials and Methods: Between 2008 and 2017, 47 laparoscopic procedures were performed with the CV discovered intraoperatively. CV were translocated cephalad, and the UPJ was carefully inspected. The Chapman's vascular hitch procedure was accomplished in the case of decreasing sizes of the pelvis and clear, visible peristalsis of the UPJ (31 patients). In the other cases, Anderson-Hynes (A-H) pyeloplasty with posterior translocation of the CV was performed (16 patients). Results: The median age at operation was 6 years (range 1-16) in VH and 6 years (range 2-17) in A-H (p = 0.4635). Prenatal dilatation of kidney was diagnosed in 18.7% of VH and 10% of A-H cases (p = 0.5474). Success was achieved in 16 (100%) patients in the A-H and in 29 (93.54%) in the VH groups. Two patients (6.5%) in VH required repeated surgery because of a misdiagnosed intrinsic obstruction. Median operation time in VH was 80 min (range 40-105) and was 105 (range 70-225) in A-H (p < 0.05). Conclusions: The intraoperative selection based on intraoperative pelvis and UPJ appearance after vessel transposition is sufficient in majority of cases. Laparoscopic vascular hitch seems to be effective and safe procedure, but can only be performed on carefully selected patients. In case of misdiagnosis, reoperation is possible with the same laparoscopic access.

Detection rate of crossing vessels in pediatric hydronephrosis: Transperitoneal laparoscopy versus open lumbotomy.

BACKGROUND: A bundle of crossing vessels (CV) supplying the lower pole of the kidney and causing mechanical obstruction of the ureteropelvic junction (UPJ) has been the subject of many discussions. During pyeloplasty, it is possible to overlook the CV. This may result in recurrent dilatation of the kidney and the need for re-surgery. OBJECTIVES: To compare the detection rate of CV in UPJ obstruction (UPJO) depending on the operational access applied (transperitoneal laparoscopy (LAP) vs open lumbotomy (OPEN)). Assessment of features that could indicate the presence of CV. MATERIAL AND METHODS: Two hundred and forty-six pediatric pyeloplasties were performed between January 2006 and July 2017 in the Department of Pediatric Surgery and Urology at the Wroclaw Medical University, Poland - 111 out of them by LAP and 135 by OPEN, on 98 girls and 148 boys. A retrospective analysis of the patient records for the detection of CV and characteristics of the CV before surgery was performed. RESULTS: Intraoperative CV causing obstruction of the UPJ in the LAP group were recognized in 34.2% (n = 38) of the patients, and within the OPEN group in 12.5% (n = 17) (p < 0.0001); 90% (n = 27) of patients with the diagnosed CV did not show congenital hydronephrosis. In 68% (n = 21) of the patients there were cases of recurrent renal colic. The presence of CV was suspected in 7.2% of kidney ultrasounds and in 12.5% in computed tomography (CT) urograms. CONCLUSIONS: The detection rate of CV in UPJO is statistically higher in LAP access than in open retroperitoneal lumbotomy. The distinguishing features of patients with CV are the lack of prenatal diagnosis for hydronephrosis and the presence of pain in the lumbar region.

Laparoscopic Heminephrectomy for Duplex Kidney in Children-The Learning Curve.

Objectives: Outcomes evolution during the learning curve of laparoscopic transperitoneal heminephrectomy in children with a duplex kidney. Materials and Methods: The data of 33 children, operated on between 2008 and 2017, with complicated duplex kidney, were subjected to a retrospective analysis. All patients were operated on by transperitoneal access using the laparoscopic technique. Patients were divided into two groups (1: subsequent operation 1-16, and 2: operations 17-33) to evaluate the learning curve. Results: There was no need for conversion. Total complications occurred in seven patients in Group 1 and 2 patients of Group 2 (p < 0.05). Two patients (6%) (both upper pole heminephrectomies) required reoperation to remove the ureter stump because of recurrent UTIs due to undiagnosed VUR to the stump (1 from each of Groups 1 and 2). Prolonged urine leakage (over 4 days) was observed in four patients (12%; all from group 1); in three patients, conservative treatment was successful, while the placement of a DJ catheter was needed in the fourth. A significant decrease of kidney function (>6%) in scintigraphy was observed in two of the 15 patients after the surgery. The time of surgery decreased from 140 (range 85-185) min in Group 1 to 125 (range 100-150) min in Group 2 (p < 0.05). Conclusions: Laparoscopic heminephrectomy is connected to the learning curve. Most complications occurred in the first 16 operations. With increasing experience, the time of operation decreased. In patients with reflux to the upper pole, referred for upper pole heminephrectomy, it is necessary to consider the removal of the ureter to the level of the vesicoureteral junction.

W-type suture in Anderson-Hynes laparoscopic pyeloplasty: a novel approach to an old technique.

INTRODUCTION: Anderson-Hynes (A-H) dismembered pyeloplasty has remained nearly unchanged since its introduction in 1949. The authors present a modification of the uretero-pelvic anastomosis as described by Anderson and Hynes. The new approach, called the W-type suture, is thought to be more watertight and associated with fewer complications than the original. AIM: To assess the effectiveness of the modification of Anderson-Hynes dismembered pyeloplasty named the W-type suture. MATERIAL AND METHODS: The research is a retrospective study of 99 patients who underwent laparoscopic A-H pyeloplasty. In 49 patients unmodified laparoscopic A-H pyeloplasty was carried out. Fifty patients underwent laparoscopic A-H pyeloplasty with the anastomosis made using the aforementioned W-type suture. To assess the effectiveness of the W-type suture, we compared urine leakage duration - a direct indicator of anastomosis tightness - and frequency of postoperative complications. RESULTS: The mean duration of urinary leakage was 3 ±1.16 days for the W-type suture anastomosis group and 3.57 ±1.14 days for the unmodified A-H pyeloplasty group (p < 0.05). The frequency of post-operative complications did not statistically significantly differ between the groups except for fever (18.4% vs. 4%; p < 0.05). CONCLUSIONS: The analysis of the collected data showed that the W-type suture might be a promising alternative to a traditional approach of performing the ureteropelvic anastomosis. Further research should be done to minimize biases present in this study, which might have influenced our results.

Anderson-Hynes pyeloplasty in children - long-term outcomes, how long follow up is necessary?

INTRODUCTION: Pyeloplasty is commonly conducted in children with uretero-pelvic junction obstruction. Standard post-operational procedure involves only a short period of time after the surgery. What is the real number of complications, including those in the long-term? What is the function of the operated kidney?The aims of this study are to assess the effectiveness of pyeloplasty and to assess the suitability of conducting long term follow-up after pyeloplasty. MATERIAL AND METHODS: 35 of 137 patients after open pyeloplasty between 1992-2006 responded to the invitation and returned for a control appointment. The median age was 8 years (range 1 month - 19 years). In 26 kidney units the disease proceeded with symptoms and in 10 cases it proceeded without symptoms. The predominant symptom was abdominal pain (n = 21). In each child both the control ultrasound and the diuretic renal scintigraphy of the kidneys were conducted. RESULTS: Regression of symptoms after the operation was obtained in 19 kidney units (73%). Improvement in scintigraphy was observed in 23 kidney units (82.1%), improvement in ultrasound was obtained in 32 (91%) kidney units. Complications which required surgical intervention occurred in 4 (11.1%) patients. One patient required operative removal of a pyelostomy tube, 2 patients (11.1%) required repeated pyleoplasty (23 and 27 months after the operation), one child required nephrectomy due to nephrogenic arterial hypertension (after 4 years). CONCLUSIONS: Statistically, there are improvements of scintigraphic function of the kidney, improvements in ultrasound examinations, and the remission of symptoms after pyeoplasty. Most complications occur within 2 years after the surgery. Long-term follow up should be continued.

Late outcomes of laparoscopic pyeloplasty: a single institution study with follow-up longer than 5 years.

INTRODUCTION: Although most urologists agree that failures after laparoscopic pyeloplasty occur usually within a year after the operation, late failures are also reported. AIM: To assess late results of laparoscopic pyeloplasty. MATERIAL AND METHODS: Seventy-eight of ninety-five patients who had been operated on between November 2001 and September 2009 were notified about the possibility of diuretic renography (DR). Excluded from the study were 3 patients who failed within 1 year after surgery, 2 others with late recurrences at 1.5 and 2.5 years postoperatively, 8 patients who were lost to follow-up immediately after the operation, 2 patients with equivocal DR after pyeloplasty and 2 cases with open conversion. Twenty-six (33.3%) patients responded to the notification. Mean follow-up was 89 months. In all patients DR, ultrasound, serum creatinine concentration, estimatated glomerular filtration rate and the assessment of symptoms were carried out. Success was defined as T1/2 ≤ 12 min and improved or stable differential renal function on DR. RESULTS: Diuretic renography revealed no obstruction in 25/26 (96%) patients. One woman was not appropriately hydrated, which rendered the result of the investigation unreliable. Mean half time to tracer clearance was 6.74 min. Mean split renal function on the operated side was 44.62%. Mean pain strength according to the VAS scale was 1.54. CONCLUSIONS: Our study seems to indicate that recurrence after laparoscopic pyeloplasty in the follow-up period longer than 5 years is very unlikely. However, until more data are available, patients should undergo long-term follow-up to receive the benefit of the operation.

Transurethral Resection of the Bladder Tumour as a Treatment Method in Children with Transitional Cell Carcinoma of the Bladder--Analysis of Our Material and Literature Review.

BACKGROUND: Bladder cancer occurs mainly in adults. In children, younger than 10 years in particular, it is very rare. OBJECTIVES: The aim of the study is to retrospectively evaluate the efficacy of transurethral resection of the bladder tumour (TUR-BT) of transitional cell carcinoma (TCC) of the bladder in children. MATERIAL AND METHODS: Transurethral resection of the bladder tumour was performed in 7 boys aged 4 to 17 years (median 12.1 years). In all cases laboratory tests, ultrasound, and cystoscopic tumour biopsy were carried out prior to the resection. Doxorubicin was additionally instilled intravesically as one dose in two patients. The Foley catheter was left in the bladder for 1 to 4 days (median 1.85 days). The follow-up period ranged from 10 months to 10 years (median 4 years). RESULTS: Papillary urothelial neoplasm of low malignant potential (PUNLMP) was diagnosed in 5 patients and urothelial papilloma in 2. Local recurrence was observed in one case two years after the resection. In all other cases complete remission was achieved. CONCLUSIONS: Transitional cell carcinoma of the bladder in children is usually benign and endoscopic treatment (TUR-BT) seems to be the treatment of choice. To determine a follow-up schedule a more substantial group of children with bladder cancer should be analysed.

Extrarenal nephroblastoma.

INTRODUCTION: Nephroblastoma is one of the most common solid tumours in children. The occurrence of extrarenal nephroblastoma is exceedingly rare. What can be defined as extrarenal Wilms' tumor must satisfy the following criteria: histologically confirmed nephroblastoma and extrarenal location. MATERIAL AND METHODS: Current data on extrarenal nephroblastoma based on a selective review of the literature. RESULTS: The retroperineal location is reported to be typical in males, whereas the inguinal region is believed to predominate in females. There are no characteristic manifestations of extrarenal nephroblastoma. The symptoms depend on the location and stage upon diagnosis. US, CT and MRI are used to detect tumours in the retroperiteneal space, inguinal, sacro-coccal and scrotal area. However, extrarenal nephroblastoma does not show characteristic radiological features. CONCLUSIONS: In absence of typical clinical presentation or conclusive imaging tests, the diagnosis is based on histology after the resection of the tumor. The recommended management of the extrarenal nephroblastoma is similar to the treatment of intrarenal nephroblastoma.

Laparoscopic pyeloplasty with cephalad translocation of the crossing vessel - a new approach to the Hellström technique.

INTRODUCTION: It is believed that lower pole crossing vessels may play an important role in the etiology of ureteropelvic junction obstruction (UPJO). A conventional operative technique, which seems to be widely used in patients with UPJO, is Anderson-Hynes (A-H) plasty with dorsal transposition of the vessel. An attractive alternative to dorsal transposition of the vessel might be its cephalad translocation. AIM: To assess the effectiveness of cephalad translocation of the crossing vessel in patients who underwent laparoscopic A-H or Y-V pyeloplasty. MATERIAL AND METHODS: Eighty-five patients were included in the study. To assess the effectiveness of cephalad translocation of the crossing vessel in patients who underwent laparoscopic pyeloplasty, the results of the procedure were compared to the results of laparoscopic pyeloplasties performed in patients without crossing vessels (control group). Success was defined as the following factors taken collectively: 80% or greater pain relief according to VAS, no sign of obstruction on intravenous urography (patent UPJ), decreasing excretion curve with T1/2 < 12 min, and improved or stable differential renal function on diuretic renography. RESULTS: The mean follow-up was 53.7 months. There was no statistically significant difference in the success rate between the compared groups (group 1 - cases with cephalad translocation of the crossing artery, and group 2 - cases without crossing vessels) in patients who underwent A-H plasty or Y-V plasty. CONCLUSIONS: The analysis of our data seems to indicate that cephalad translocation of the anterior crossing vessel gives good therapeutic results in patients who undergo laparoscopic pyeloplasty.

An evaluation of the effectiveness of external urethral meatus incision in girls with an anterior deflected urinary stream and symptoms of detrusor overactivity.

BACKGROUND: Urethral stenosis or abnormalities in the external urethral meatus in girls may lead to serious functional bladder outlet obstruction and recurrent urinary tract infections. OBJECTIVES: The aim of the study was to analyze the efficacy of meatotomy in girls with an anterior deflected urinary stream (ADUS) and symptoms of detrusor overactivity. MATERIAL AND METHODS: A group of 67 girls between the ages of 5 and 16 (mean age: 8.6 years) with symptoms of detrusor overactivity participated in the study. The girls were treated with oxybutinin in the years 2010-2011. The group included 37 girls with ADUS (the ADUS group) while the remaining 30 girls (the OXY group) were found to have a normal urinary stream. In the ADUS group an external urethral meatus incision was performed. The follow-up period was three months. The presence of urinary tract infections (UTI) as well as nocturnal bedwetting and daytime incontinence were analyzed before and after treatment. RESULTS: After three months, in the ADUS group no UTI was found in 12 children (32%) (p < 0.05), including 11 patients with prior febrile UTI (p < 0.05). Recovery from daytime urinary incontinence was observed in 20 girls (54%) and recovery from nocturnal bedwetting in 8 girls (22%). In the OXY group no infections were found in three girls (10%); recovery from daytime urinary incontinence was noted in 21 girls (70%) and from nocturnal bedwetting in 10 girls (33%). CONCLUSIONS: Girls with symptoms of detrusor overactivity accompanied by an anterior deflected urinary stream experience UTIs and fever more often than girls with detrusor overactivity and a normal urinary stream. An incision in the external urethral meatus in girls with ADUS and detrusor overactivity seems to be effective treatment for recurrent urinary tract infections, especially febrile ones.

A comparison of renal function outcomes after nephron-sparing surgery and radical nephrectomy for nonsyndromic unilateral Wilms tumor.

OBJECTIVE: To better understand the impact of nephron-sparing surgery (NSS) on renal function in patients with nonsyndromic unilateral Wilms tumor (uWT), a group of such patients treated with NSS were compared with a stage-matched cohort managed with radical nephrectomy (RN). The recommended management of nonsyndromic uWT is RN. However, NSS may decrease the risk of long-term renal disease and associated comorbidities. MATERIALS AND METHODS: An international, multi-institutional review was conducted of nonsyndromic uWT cases managed with NSS and compared with a stage-matched RN cohort. Data were collected on demographics, oncologic characteristics and outcomes, serum creatinine, and estimated glomerular filtration rate (eGFR) calculated via Schwartz formula. RESULTS: Fifteen patients who underwent NSS (6 females and 9 males) met study criteria and were diagnosed at a median age of 2.5 years (range, 0.2-8.2 years) and followed for a median of 8.4 years (range, 0.5-31.8 years). The stage-matched RN cohort consisted of 15 patients (8 females and 7 males) diagnosed at a median age of 3.7 years (0.3-7.4) and followed for a median of 2.1 years (0.6-10.5 years). The median preoperative eGFR was 91.7 (39.4-237.7) and 149.9 (93.8-215.9) for NSS and RN, respectively, P=.026. The median eGFR at last follow-up was 135.3 (57.5-185.8) and 131.0 (98.6-161.2) for NSS and RN, respectively, P=.95. The median change in eGFR during the study period was a gain of 28.6 (-51.9 to 83.0) for the NSS cohort vs a loss of 19.1 (-54.7 to 25.2) for the RN cohort, P=.007. CONCLUSION: In a highly selected patient population with nonsyndromic uWT, NSS provides excellent renal function preservation when compared with RN. These data require validation via prospective investigation on a larger scale.

The distribution of interstitial cells of Cajal in congenital ureteropelvic junction obstruction.

PURPOSE: The authors analysed the distribution of c-kit-positive interstitial cells of Cajal (ICCs) in obstructed ureteropelvic junction (UPJ) and its age-related changes. METHODS: Twenty specimens were obtained from children with intrinsic ureteropelvic junction obstruction (UPJO), at the average age of 8.1 years (8 months-16.8 years), fixed in formalin and embedded in paraffin. Five control samples were taken from children at the average age of 2.3 years (2.4 months-7.4 years). All specimens were analysed by the immunohistochemistry test with light microscopy with respect to c-kit expression. The distribution of c-kit-positive ICCs in the two groups was compared and the correlation between the distribution of c-kit-positive ICCs and the patients' age in UPJO cases was analysed. The results were examined by Yates' χ(2) test, Mann-Whitney U test, and t test for Pearson's correlation coefficient. A P value < 0.05 was considered as statistically significant. RESULTS: No statistically significant differences were found in the distribution of c-kit-positive ICCs between UPJO and the control group. No correlation was established between the age of patients with UPJO and the distribution of c-kit-positive ICCs. CONCLUSION: No distributional difference found in obstructed and unobstructed UPJ seems to indicate that UPJO is not associated with anomalous distribution of c-kit-positive ICCs. Age-related changes in the expression of c-kit-positive ICCs are equally distributed in obstructed UPJ.

Simultaneous laparoscopic adrenalectomy and laparoscopic nephron-sparing surgery - new experience with port placement.

The aim of the study was to describe simultaneous laparoscopic adrenalectomy and laparoscopic nephron-sparing surgery, to discuss the details of a convenient laparoscopic approach and the way of port placement, as well as to present a review of the literature concerning combined laparoscopic procedures. A 72-year-old woman was admitted to our department because of a tumor of the right adrenal gland and a small tumor of the right kidney. The patient underwent simultaneous laparoscopic adrenalectomy and laparoscopic nephron-sparing surgery. The postoperative period was uncomplicated. The patient was discharged from the hospital on the 4(th) postoperative day. We believe that the proposed way of trocar placement would help to avoid a 'rollover' problem between the laparoscope and a Satinsky clamp or a 'crossing swords' problem between a Satinsky clamp and manipulators.

Laparoscopic Anderson-Hynes procedure as a treatment of ureteropelvic junction obstruction caused by fibroepithelial polyp.

Fibroepithelial polyps (FEPs) are rare benign ureteral neoplasms of mesodermal origin. As an intrinsic cause of ureteropelvic junction obstruction (UPJO) they are very uncommon. Excretory urography and diuretic renography used by many urologists to diagnose a UPJO may not detect the ureteral polyp. We present a case of ureteropelvic junction obstruction caused by a fibroepithelial polyp, which was not diagnosed preoperatively. The patient underwent successful laparoscopic excision of the polyp with Anderson-Hynes pyeloplasty. We believe that laparoscopy is a useful, minimally invasive operative technique in the treatment of FEPs and may be considered a procedure of choice in large polyps, in which cases the endoscopic procedure is difficult or impossible to perform.

Crossed renal ectopia: can it be a diagnostic problem?

Crossed renal ectopia (C-RE) is a rare congenital anomaly in which both kidneys are located unilaterally. The crossed kidney is situated on the side opposite to its ureteral orifice and usually lies below the normal kidney. The frequency of this malformation is estimated at 0.05% to 0.1%. Most of the patients remain asymptomatic. In other cases C-RE is diagnosed incidentally on routine ultrasonography, due to the presence of unspecific symptoms. The diagnosis of C-RE is possible due to a wide range of imaging techniques: US, IVU, CT, MRI, and TcDMSA scan. Among them IVU, CT, and MRI have the highest degree of confidence. The aim of this retrospective study was to present our own experience with 5 children affected with C-RE, emphasizing the differences in clinical picture and low sensitivity of ultrasound images. In all of them the final diagnosis was established by IVU or MRI.