BACKGROUNDBladder leiomyoma is an uncommon type of bladder neoplasms. Most publications are reports of isolated cases. The influence of tumor size on patients' early symptoms was seldom analyzed. We aim to investigate the clinical characteristics of bladder leiomyoma and the influence of tumor size on patients'symptoms in Chinese population.

METHODSWe reviewed the medical records of eight patients diagnosed with bladder leiomyoma at our department, collected 53 cases from Chinese National Knowledge Infrastructure (CNKI), Wangfang data base, and Chinese Biological Medicine Disk, and performed a pooled analysis. The clinical characteristics of the patients were analyzed and then classified into symptomatic and asymptomatic groups. The association between tumor size and the occurrence of symptoms was evaluated. Furthermore, Logistic regression model was constructed to discriminate variables.

RESULTSWomen comprised the majority of the patients (49/61, 80.3%). The mean age and tumor size were (42.3 ± 14.0) years and (45.0 ± 25.7) mm, respectively. Among all the symptoms, irritative symptoms occurred most frequently (37.7%, 23/61), followed by obstructive urinary symptoms (31.1%, 19/61), hematuria (24.6%, 15/61), and abdominal bulge or pain (14.8%, 9/61). In our study, patients who were 45 years old or younger tended to be asymptomatic compared with elder ones (14/36 vs. 3/25, P = 0.021). The histological, as well as anatomical, location of tumor, did not show significant differences between symptomatic and asymptomatic patients (P = 0.306 and 0.700). Tumors larger than 30 mm in the greatest diameter would cause clinical symptoms such as obstructive urinary symptoms (P = 0.048) and irritative symptoms (P = 0.037). Logistic regression confirmed the association between tumor size and the occurrence of symptoms, which was related with age.

CONCLUSIONSBladder leiomyoma occurs mainly in women and most frequently with irritative symptoms. The occurrence of symptoms is related to tumor size rather than the location. In this setting, patients with endovesical tumors smaller than 30 mm in the greatest diameter tended to be asymptomatic, which were usually treated with transurethral resection of bladder tumor.