Fibroepithelial polyps are uncommon benign tumors derived from mesenchymal tissue within the urinary tract. While advances in pediatric endoscopic techniques have improved detection and management, fibroepithelial polyps of the upper urinary tract remain exceedingly rare. They account for only about 0.5% of ureteropelvic junction obstruction (UPJO) in children, and to date, approximately 60 cases have been reported in the literature. These polyps can present with nonspecific symptoms such as flank pain, hematuria, or lower urinary tract symptoms, often mimicking more common obstructive pathologies. Given their rarity, no standardized treatment protocol exists. In this report, we introduce the first known case of using Thulium laser ablation to manage broad-based, multilobulated fibroepithelial polyps in the pediatric upper urinary tract, offering a potential new direction in minimally invasive therapy.

An 11-year-old boy presented with several months of dysuria, urinary frequency, and nocturia, along with intermittent crampy upper abdominal pain, nausea, and vomiting over the past three weeks. Renal ultrasound revealed significant left-sided hydronephrosis. Further investigation via ureteroscopy identified broad-based, multilobulated fibroepithelial polyps causing left UPJO. The patient underwent flexible ureterorenoscopy and endoscopic ureterotomy with Thulium laser ablation (Figure. 1). A three-month follow-up demonstrated complete symptom resolution and no residual hydronephrosis (Figure. 2).

Fibroepithelial polyps, while rare, can be a clinically significant cause of pediatric UPJO. They are believed to be congenital in origin and may remain asymptomatic until obstructive complications arise. Due to the limited number of reported cases, there are no clear treatment guidelines. Endoscopic excision is generally the preferred approach due to its minimally invasive nature and rapid recovery. Holmium laser is frequently employed for excising single, pedunculated polyps; however, broader and more complex lesions have traditionally required open or laparoscopic pyeloplasty. In contrast, our case demonstrates the feasibility and success of using Thulium laser ablation for treating a broad-based, multilobulated lesion endoscopically, avoiding more invasive surgical options.

This case highlights the successful application of Thulium laser ablation in managing complex fibroepithelial polyps of the ureter in a pediatric patient. The complete resolution of both symptoms and hydronephrosis suggests that this technique may serve as a promising, less invasive alternative for similar cases in the future.