Pediatric urothelial bladder neoplasm

Introduction: Urothelial bladder neoplasm (UBN) is an uncommon lesion in children and adolescents, without established follow-up protocol defined for this patient group.

Objectives: To report our experience and long-term follow-up data on pediatric patients with urothelial carcinoma of the urinary bladder.

Methods: In this retrospective two center study, we analyzed the perioperative and long-term follow-up data of nine pediatric patients, who presented with neoplasms of urothelial origin within the urinary bladder between 2000 and 2021.

Results: Nine patients were identified with a mean age of 11.9 years (range 4-19 years) and median follow up of 48 months (range 12-160 month). 7 were male. Gross hematuria was the most common presenting symptom, occurring in 6 patients, followed by accidental finding on US, performed for other reasons. Cystoscopy was performed under general anesthesia, and transurethral resection of the bladder tumors was carried out in the same session. All patients had a solitary tumor with a mean size of 11 mm (range 6-15 mm). Pathology revealed 3 cases of papillary urothelial neoplasm of low malignant potential (PUNLMP), 5 cases of low grade (LG) noninvasive urothelial carcinoma (UC) and one case of high-grade (HG) UC invading lamina propria (pT1). All 8 patients with low grade tumor underwent follow up according to adult follow-up protocols without tumor recurrences to date. The single patient with HG pT1 UC, a 14-year-old female after renal transplantation, who was not eligible for intravesical bacillus Calmette-Guerin (BCG) installations due to immunosuppression, underwent 6 sessions of Radiofrequency-induced Thermo-chemotherapy with mitomycin, without complications. She had no recurrence to date, during a 4-year post treatment follow up.

Conclusion: Pediatric non muscle invasive bladder cancer (NMIBC), seems to have a good prognosis with infrequent recurrences, which might be in favor of a more spacious follow up plan with less invasive diagnostic modalities as opposed to adult NMIBC population. To the best of our knowledge this is the single description of Heated Intravesical Chemotherapy efficacy for HG UC in the pediatric population.