The presence of trigonal non-keratinising squamous metaplasia is not associated with menopausal or estrogen status but may be associated with urinary tract infection in women

Abstract

Objective

Squamous metaplasia (SM) at the bladder trigone is often seen during cystoscopy in women. It has previously been described as a normal finding in the literature under the influence of estrogen; however, metaplastic change in epithelium can be activated in response to infection. In this study, we hypothesise that trigonal SM is indicative of urinary tract infection (UTI) in pre- and post-menopausal women irrespective of estrogen status.

Study Design

Descriptions of the bladder trigone were retrospectively reviewed in the surgical notes of pre- and post-menopausal women who underwent cystoscopy for presence of SM. Results of urine and tissue cultures were also reviewed with UTI being defined as a positive urine and/or bladder tissue culture.

Main Outcome Measures

The statistical relationship between the presence of trigonal SM and culture positive UTI.

Results

97 women were included with 39 post-menopausal (40%) and 58 pre-menopausal (60%). SM had a 62% positive predictive value of UTI, and a negative predictive value of 73% (sensitivity = 93%, specificity = 76%). Chi-squared showed that there is a statistically significant relationship between trigonal SM and UTI p = .015. Bladder tissue was more likely to identify a uropathogen in women with severe SM. We found no significant relationship between estrogen status and the presence of SM (p = .866).

Conclusions

This study shows that the cystoscopic appearance of SM is associated with infection in the bladder independent of menopausal status or exposure to externally taken estrogen. This may be a particularly helpful finding in women with recurrent symptoms of UTI but negative culture results.