Comparison of the prevalence and histology between primary benign bladder tumors and recurrent benign lesions after transurethral resection of malignant bladder tumors

Abstract

Background: Benign bladder tumors are rare disease entities, and insufficient studies have assessed their epidemiological characteristics. The authors investigated the prevalence of benign bladder tumors by retrospectively investigating pathology reports of transurethral resection of bladder tumor (TURBT) procedures over the past 20 years.Methods: We analyzed 1,674 pathology reports of TURBT conducted in 1,160 patients from January 1, 2000, to April 30, 2022. The prevalence of benign tumors and histological classification according to the presence of primary (group 1) and recurrent (group 2) bladder lesions were retrospectively investigated. Results: The mean age of patients was 65.2±11.5 years, and 1,284 cases (79.1%) were in men. Benign bladder tumors comprised 278 cases (248 patients) accounting for about 17.1% of the total TURBT cases (278/1,624). Furthermore, 184 patients (16.0%, 184/1,147) belonged to group 1 and 78 patients (27.4%, 78/285) belonged to group 2. Among all benign lesions that underwent TURBT, cystitis was the most common (41.0%, 114/278), and this rate was higher in group 2 (64/184 [34.8%] vs. 50/94 [53.2%], p<0.001). The prevalence of non-neoplastic lesions was higher in group 1 (44/184 [23.9] vs. 11/94 [11.7%], p<0.001). There was no difference in the prevalence of noninvasive urothelial neoplasms between the two groups (22/184 [12.0%] vs. 8/94 [8.5%], p=0.86).Conclusions: The probability of benign lesions in TURBT was 17.1%, among which cystitis was the most common. When TURBT was performed for recurrent lesions, the frequency of benign tumors was higher than that of primary benign bladder tumors.