Utilizing ultrasonography in the diagnosis of pediatric fibroepithelial polyps causing ureteropelvic junction obstruction

Unmasking Ureteral Polyps: Insights From a Case Series

Fibroepithelial polyps in the urinary tract are a rare cause of obstructive uropathy with fewer than 130 cases reported in the literature. In our series, we describe polyps that were missed on preoperative imaging and later found in the operating room during pyeloplasty. It is critical for urologists to be aware of polyps as a potential source of obstruction as they can increase the complexity of a reconstruction and, if missed, may result in a failed repair and persistent obstruction. We hypothesize that performing a retrograde pyelogram prior to ureteric reconstruction will facilitate diagnosis prior to surgical repair.

Preoperative diagnosis, treatment, and outcomes of FEPs of ureters in children: a 13-year retrospective study based on data at a large pediatric medical center

Purpose

To describe our experience in handling cases of children with fibroepithelial polyps (FEPs) of ureters. We specifically present preoperative diagnosis approaches, provide a clear definition of this entity and its outcomes following treatment.

Method

Clinical data of children with FEPs who were consecutively treated at Beijing Children's Hospital from January 2006 to May 2019 were retrospectively analyzed in this study. The clinical data reviewed included diagnostic, intraoperative, and follow-up data.

Results

Of the 2653 children with surgery for hydronephrosis reviewed, 48 (1.8%) cases of FEPs of the ureters were identified, with a mean age of 109 ± 34.7 months. Among them, males accounted for 95.8%, left side for 81.3%, and proximal ureteral polyps for 97.9%. Notably, 70.8% of patients had only 1 polyp and the median size of the polyps was 2.1 ± 1.8 cm. All patients underwent ultrasound before surgery, which revealed the existence of polyps in 29 (60.4%) children. These polyps were completely resected surgically. The mean follow-up was 82 months (range of 6–153 months) and no cases of recurrences of polyps were seen after surgery during follow-up. The rate of other long-term complications was 9.3%.

Conclusions

In conclusion, FEPs are one of the important causes of hydronephrosis in children. Ultrasound is effective for preoperative diagnosis achieving higher true positive rates than other diagnostic methods. Although the recurrence rate of polyps and symptoms are low after complete resection in children, long-term follow-up is advocated to the adolescence stage to monitor the incidences of urinary tract infections, ureteropelvic junction obstruction and stone formation.

Electronic supplementary material

The online version of this article (10.1007/s00345-020-03379-6) contains supplementary material, which is available to authorized users.

Fibroepithelial Polyp in a Child: A Rare Pathology of Upper Urinary Tract Obstruction

Fibroepithelial polyp is a rare benign tumor of the urothelial system that originates from the mesoderm. Polyps are usually small and located in the upper urinary tract and ureteropelvic junction. However, in the pediatric population, such polyps are more common in the posterior urethra and will present with symptoms of urinary tract obstruction. Some will present with flank pain and hematuria, resembling symptoms of ureteric stones. In this case, we discuss a nine-year-old boy presenting with complaints of flank pain and hematuria for one year. Following laboratory and radiological investigations, the left ureter was dilated at the mid-lumbar region with an anteroposterior diameter of 2.3 x 0.6 cm and a left renal pelvis anteroposterior diameter of 2.2 cm. An ultrasound scan identified an intraluminal lesion suspected to be a fibroepithelial polyp. Management was carried out via retroperitoneal surgery with upper ureteral resection and end-to-end anastomosis. Postoperatively, the patient’s symptoms improved, and a subsequent ultrasound scan and renal function test showed improvement of the left hydroureter and hydronephrosis.

Iatrogenic Fibroepithelial Polyps in Children With Hydronephrosis

OBJECTIVE

To discover the possible factor of the iatrogenic fibroepithelial polyps (FEPs).

MATERIALS AND METHODS

A retrospective chart review of 28 pediatric patients who have undergone pyeloplasties for ureteropelvic junction obstruction with pathologically proven FEPs was performed from January 2009 to June 2016 at our hospital. Among them, 6 patients without apparent FEPs at the time of the first pyeloplasty were found to have FEPs at the time of reoperation. The medical history and clinical, diagnostic, intraoperative, pathologic, and follow-up data of the 6 patients were reviewed.

RESULTS

All iatrogenic FEPs were located proximal to the anastomotic stoma. On pathological examination, the size of the FEPs ranged from 1.5 to 3.5 cm. The FEPs were pink, grayish-white, or tan-gray in color and cauliflower-like in shape. Microscopically, they arose from the submucosa and consisted of a layer of normal transitional epithelium covering a fibrovascular stromal core showing sparse vascularity and prominent edema. The mean follow-up period was 47 months (range, 4-82 months). All patients' symptoms disappeared and the function of the affected kidney was preserved after the second pyeloplasty. No patients developed FEP recurrence.

CONCLUSION

Nephrostomy may associate with iatrogenic FEPs in young children. Iatrogenic FEPs are a specific type of polyp that grows rapidly within a very short time. Pathologically, iatrogenic FEPs are the same as other types of FEPs.

Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: a report of five cases

INTRODUCTION

Hydronephrosis is a common disease in children and may be caused by ureteral fibroepithelial polyps (UFP). Ureteral fibroepithelial polyps are rare in children and are difficult to precisely diagnose before surgery. Surgical treatment for symptomatic UFP is recommended. At the present institution, retroperitoneal laparoscopy has been used to treat five boys with UFP since 2006.

OBJECTIVE

To highlight the significance of UFP as an etiological factor of hydronephrosis in children and evaluate the applicative value of retroperitoneal laparoscopy in the treatment of children with UFP.

METHODS

Between 2006 and 2013 five boys underwent retroperitoneal laparoscopy at the present institution. They were identified with UFP by review of the clinical database. Detailed data were collected, including: radiographic studies, gross anatomical pathology, and pathology and radiology reports. All boys had been followed up at least every 6 months.

RESULTS

All of the boys were aged between 7 and 16 years (mean 9.8 years). The main symptoms were flank pain (all five) and hematuria (three). Radiographic examination showed that all of the boys presented with incomplete ureteral obstruction and hydronephrosis. The ureteral fibroepithelial polyps were located near the left UPJ or the left proximal ureter. All of the boys had the UFP removed: three underwent retroperitoneal laparoscopic dismembered Anderson-Hynes pyeloplasty and polypectomy, and two had retroperitoneal laparoscopic ureteral anastomosis. These polyps were all on the left side and between 15 and 35 mm in length (mean 22 mm) (Figure). All of the boys recovered well and were discharged from hospital. The postoperative histological report confirmed that the specimens were UFP. Hydronephrosis was periodically assessed by ultrasonography (using the same method as pre-surgical ultrasonography) after surgery. Mean follow-up was 33 months (range 6-58 months) and no complications were found afterwards.

CONCLUSIONS

Ureteral fibroepithelial polyps are rare but rather important as they can cause UPJ obstruction, which often manifests as hydronephrosis. It is most important to confirm the site of ureteral obstruction before surgery as this may have an effect on the surgical management. It is recommended that UFP be successfully managed in children with retroperitoneal laparoscopy.

Diagnosis and management of ureteral fibroepithelial polyps in children: a new treatment algorithm

INTRODUCTION

Fibroepithelial polyps are benign mesenchymal tumors arising from the urinary tract. With the advent of endoscopy in the pediatric population, more reports of endoscopic diagnosis and treatment have appeared.

OBJECTIVE

The present study reports experience with the diagnosis and treatment of fibroepithelial polyps of the upper urinary tract in the pediatric population. Incorporating past experience from literature, we propose an algorithm to guide the clinical diagnosis and treatment plan.

STUDY DESIGN

Four pediatric patients undergoing pyeloplasty for ureteropelvic junction (UPJ) obstruction were diagnosed with ureteral polyps. Their demographics, radiologic, surgical and pathologic information were reviewed. In addition, a comprehensive literature search using the MEDLINE database yielded 37 reports containing 126 cases of ureteral polyps, including 5 series with 57 cases and 9 cases of synchronous bilateral ureteral polyps.

RESULTS

Of 123 pediatric patients undergoing pyeloplasty from 2008 to 2013, four (3.3%) were found to have fibroepithelial polyps of the upper urinary tract. All patients were male and the mean age of presentation was 12 years. Ureteral polyps predominantly occurred unilaterally in the left ureter (75%) and one case of bilateral ureteral polyps was encountered. Along with three other recent case series [1-3], the combined incidence of ureteral polyps in patients undergoing evaluation for ureteral obstruction was 5.2%. Intraoperative retrograde pyelogram was used to identify filling defects in 4 of 5 affected ureters (see Figure). Ureterorenoscopy was performed in all three patients with filling defects for polyp mapping along the ureter and evaluation of the macroscopic polyp appearance. Based on ureteroscopic findings, Holmium laser polypectomy was performed in two patients with single, pedunculated polyps. Anderson-Hynes dismembered pyeloplasty was performed in three patients with broad based, multilobulated polyps too large for endoscopic treatment and in one patient for undiagnosed polyp prior to pyeloplasty.

DISCUSSION

The present study finds that the 5.2% combined incidence of ureteral polyps in contemporary reports may be higher than previously described [4]. Retrograde pyelogram was an effective tool in diagnosing ureteral polyp and ureteroscopy can be employed if ureteral polyps are suspected for both diagnostic and therapeutic purposes. Although clinical experience is limited, endoscopic laser treatment seems to be effective for the single, pedunculated ureteral polyps, while dismembered pyeloplasty is required for the broad based, multilobulated polyps. The study was limited by the rarity of ureteral polyps. Future multi-institutional collaborative studies are required to validate the diagnostic and treatment algorithm proposed.

CONCLUSION

Ureteral polyps cause approximately 5% of UPJ obstruction in the pediatric population. Diagnosis can be made in certain cases by intraoperative retrograde pyelogram. If a filling defect is encountered, ureteroscopy is indicated for polyp mapping. The treatment modality is dictated by the endoscopic appearance of the ureteral polyp.

Antenatal mild hydronephrosis with subsequent polyp of the upper ureter in a child presenting with recurrent Dietl's crisis

We report a 7-year-old boy who had antenatally diagnosed and postnatally confirmed asymptomatic right congenital hydronephrosis secondary to ureteropelvic junction obstruction with the anteroposterior diameter ranging from 7 to 15 mm on serial ultrasound scans till the age of 6 years. He then presented with recurrent attacks of Dietl's crisis almost every month in the seventh year of his life and eluded diagnosis for over a year at various national hospitals, and ended up with an international referral to us. Investigations of the acute attacks clinched the diagnosis of ureteral polyp causing intermittent crisis and he underwent segmental resection and reconstruction in the form of dismembered Anderson-Hyne pyeloplasty with good recovery. Our case revealed that prenatally detected hydronephrosis may worsen after spontaneous postnatal improvement and a polyp acting as a flip valve may produce intermittent hydronephrosis and symptoms later in life. The child should undergo urgent investigations during acute symptoms.