Papillary Urothelial Neoplasia with Low Malignant Potential (PUNLMP) in a 9-year-old Child: A Case Report and Review of Literature

Papillary bladder tumors in children are rare. They comprise urothelial papilloma, inverted urothelial papilloma, papillary urothelial neoplasm of low malignant potential (PUNLMP), non-invasive low grade papillary urothelial carcinoma, and non-invasive high grade papillary urothelial carcinoma. PUNLMP are the commonest bladder tumors in children. They are typically solitary, small, non-invasive lesions that do not spread. The majority of children present with urinary bladder masses and lower urinary tract symptoms such as hematuria, dysuria, frequent urination, or urgency. Ultrasound is the first line imaging tool for assessing bladder lesions, followed by cross-sectional imaging examinations such as computed tomography or magnetic resonance imaging if the diagnosis is uncertain. The bladder tumor is typically removed through the urethra. We describe a 9-year-old boy who presented with painless gross hematuria for three months. An ultrasound revealed a left bladder tumor, which was treated with a transurethral resection of bladder tumor (TURBT) laser. Histopathology of the removed bladder tissue showed a well-circumscribed PUNLMP, with an immune-profile positive for GATA-3, p63, and CK7, and a low proliferative index. The PUNLMP recurred in the trigone of the bladder a month later. Pediatric PUNLMP is an exceptionally rare neoplasm in children with a low recurrence rate that is amenable to treatment. Pediatric PUNLMP diagnosis is to be suspected in any child with painless hematuria. Recurrence is part of the spectrum of PUNLMP. Hence, follow up of any diagnosed case with PUNLMP is imperative. Given the very small number of cases, it is difficult to determine a clear treatment and follow-up strategy; more cases and research are required to develop specific guidelines.