The pathogenesis of bladder detrusor endometriosis

OBJECTIVE: The purpose of this study was to ascertain whether bladder detrusor endometriosis originates intraperitoneally in the vesicouterine pouch or subperitoneally in the vesicovaginal septum and whether an association exists with uterine adenomyosis. STUDY DESIGN: Data were collected on clinical, diagnostic, and surgical characteristics of 40 women who were evaluated for primary, histologically confirmed, full-thickness detrusor endometriosis. RESULTS: In 19 of the 20 women who underwent surgery, the anterouterine pouch was partially or totally obliterated with the nodule that was located in the posterior wall or dome of the bladder, well above the uterine isthmus, and adherent to the anterior uterine wall or fundus. With one exception, pelvic ultrasonography, cystoscopy, intravenous pyelography, magnetic resonance imaging, and computed tomography identified the lesion cranially with respect to the vesicovaginal septum and excluded uterine adenomyosis. CONCLUSION: Vesical endometriosis seems to originate from the implantation of regurgitated endometrial cells in the anterior cul-de-sac and not to be associated with uterine adenomyosis. The metaplasia of subperitoneal mullerian remnants and the uterus-vesical adenomyosis extension theories are not compatible with most imaging, surgical, and pathologic findings.