Clinical Case

A 21-month-old circumcised boy presented to the outpatient clinic for evaluation after a febrile urinary tract infection. Six weeks prior, he presented to an outside emergency room with a fever of 104.9 °F and a febrile seizure. He was transferred to a local children’s hospital and admitted. The patient tested positive for rhino/enterovirus and respiratory syncytial virus. He clinically improved and was discharged. However, he continued to have lower-grade fevers and a voided urine specimen was obtained. This revealed positive leukocyte esterase and he was treated for a urinary tract infection due to abnormal test results. He was then referred to urology, where renal/bladder ultrasound was obtained and revealed a 1.5-cm nonmobile echogenic bladder mass at the posterior bladder near bladder neck region (Figure 1, A and B). There was no upper tract dilation observed on ultrasound.

The patient was brought to the operating room for further characterization of this bladder mass. On cystoscopy, a white, smooth botryoidal lesion projected into the bladder on a broad stalk based at the bladder neck. Due to the broad base and mobile intravesical component, loop resection was not deemed safe or effective. The base of the tumor was biopsied. Biopsy pathology showed no evidence of malignancy and was suggestive of but not diagnostic for fibroepithelial polyp (FEP). The patient returned to the operating room days later and repeat attempts for transurethral excision were performed with holmium laser at the tumor base. Due to the bulbous and mobile intravesical component, visualization was limited and open excision of the residual tumor was performed (Figure 2). Final pathology of the excised tumor confirmed an FEP. His postoperative course has been uncomplicated, with no evidence of recurrence on ultrasound or observed voiding symptoms with 6 months of follow-up.

Discussion

Pediatric bladder masses are highly uncommon and, with the exception of bladder/prostate rhabdomyosarcoma, are typically benign.^1-5 Typical clinical presentations include dysuria, hematuria, urinary frequency, obstructive symptoms, or lower abdominal pain, although they can be incidentally found as well. Ultrasound is the most common initial imaging modality, but voiding cystourethrogram can aid in diagnosis as well.^1,5 Evaluation with a full bladder is important with ultrasonography to ensure a more thorough evaluation. However, ultrasound and other imaging studies cannot reliably predict bladder mass pathology in this population, and tissue diagnosis via biopsy or excision is required.

The differential for pediatric bladder masses includes rhabdomyosarcoma, urothelial carcinoma, inflammatory myofibroblastic tumors, nephrogenic adenoma, and FEP, among others.^1-4 Tissue sampling is critical for ruling out rhabdomyosarcoma, which is often unresectable at presentation, and multimodal therapy is employed in an organ-sparing strategy.² Urothelial carcinoma, the most common bladder tumor in adults, is exceedingly rare and, when present, is typically noninvasive and low grade.³

FEPs are rare, male-predominant, benign tumors of mesodermal origin, occurring at all levels of the urinary tract from the renal calyces to the anterior urethra.^5-8 Across all age groups, FEPs are most frequently identified in the upper ureter or renal pelvis, while in children, FEPs are more likely to be located in the male posterior urethra and can result in bladder outlet obstruction.⁷ Boys with urethral FEPs typically present with hematuria, intermittent obstructive voiding complaints, and urinary retention. In girls, where reported cases are sparse, the most common presentation is an interlabial mass.⁸

Depending on the location, FEP size, and the size of the patient, they can be amenable to transurethral resection with either electrocautery or laser. However, large FEPs may require cystotomy to remove the specimen. If resected at the base of the stalk, recurrence is rare. There is debate about surveillance for recurrence. Ultrasound may be sufficient as use of cystoscopy in pediatric patients generally requires general anesthesia.