Accuracy of Transvaginal Ultrasound Compared to Cystoscopy in the Diagnosis of Bladder Endometriosis Nodules

OBJECTIVES: To evaluate the accuracy of transvaginal ultrasound (TVUS) in predicting detrusor infiltration and ureteral meatus involvement in patients with bladder endometriosis (BE) to select which cystoscopic procedures could be avoided and, secondarily, to assess the relationship between symptoms and the characteristics of nodules and the association of BE with other forms of endometriosis. METHODS: Patients with BE diagnosed by TVUS were classified according to detrusor infiltration: BE with partial involvement of the muscular layer (group 1) and total muscular layer involvement with bladder protrusion (group 2). We analyzed the accuracy of TVUS compared with subsequently performed cystoscopy, the correlation with symptoms, and the association with other forms of endometriosis. RESULTS: Among the 22 patients included, TVUS showed 9 patients with BE nodules partially affecting the detrusor (group 1) with normal cystoscopic findings (TVUS negative predictive value, 100%). Transvaginal ultrasound detected 13 nodules with total involvement, all visible by cystoscopy (TVUS positive predictive value, 100%). Transvaginal ultrasound also identified ureteral orifices that were free of involvement at greater than 10 mm from the BE nodule in 21 of 22 women (TVUS sensitivity, 95%). Ultrasound criteria for adenomyosis and endometriosis in other locations were present in 20 of 22 patients. CONCLUSIONS: Transvaginal ultrasound can identify the infiltration of BE nodules in the bladder wall and predict cystoscopic findings with great accuracy. Nodules that partially affect the muscular layer have normal cystoscopic findings, thereby obviating the need for this procedure. Bladder endometriosis nodules are commonly associated with other forms of endometriosis and do not usually affect the ureteral meatus.