Benign urinary bladder masses: rare entities

Abstract Background 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. Methods 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. Results 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. Conclusion 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.