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.