Benign urinary bladder masses: rare entities

This study aimed to present the characteristics and outcomes of benign urinary bladder masses, as well as the characteristics of the patients diagnosed with such lesions.

A single-center, cross-sectional, retrospective study was conducted. The study involved patients who underwent transurethral resection of the primary bladder tumor over a four-year period (May 2017–2021) and were subsequently diagnosed with a benign bladder lesion.

Out of 478 patients who underwent transurethral resection of the primary bladder tumor, 26 (5.4%) were diagnosed with a benign bladder lesion. The most common benign bladder lesion was urothelial papilloma (50%, 13 patients). The majority of patients with urothelial papilloma were men (76.9%) and had a history of smoking (61.5%). The mean age was 62 years. Most were diagnosed accidentally (69.2%), while others presented with hematuria (23.1%) or dysuria (7.7%). Most urothelial papillomas had a macroscopic polypoid appearance (61.5%), and most of them were solitary (84.6%), with a mean size amounting to 1 cm. Only one patient experienced a recurrence and developed papillary urothelial neoplasm of low malignant potential (PUNLMP). Cystitis cystica/glandularis and polypoid cystitis were the second most commonly diagnosed benign bladder lesion, each identified in 3 patients. Singular cases of leiomyoma, inflammatory myofibroblastic tumor, chondroma, paraganglioma, villous adenoma, eosinophilic cystitis (pseudotumor), and ectopic prostatic tissue are described.

Benign bladder lesions constitute a group of various rare entities that can clinically and radiologically mimic urothelial carcinoma, but mostly show a good prognosis and a low incidence of recurrence.