False-normal appearance of the endometrium on conventional transvaginal sonography: comparison with saline hysterosonography.

OBJECTIVE: The objective of this article is to assess the utility of transvaginal saline hysterosonography in patients presenting with a normal-appearing endometrium on conventional transvaginal pelvic sonography.
MATERIALS AND METHODS: Between August 1997 and October 1999, 180 patients underwent saline hysterosonography for abnormal vaginal bleeding. All patients had conventional transvaginal pelvic sonography before saline hysterosonography. On conventional transvaginal sonography, the sonographic appearance of the endometrium was classified according to the following parameters: normal or abnormal thickness, homogeneous or heterogeneous echogenicity, bulbous contour, discontinuous, or obscured. A comparison was performed between the endometrial appearance on conventional transvaginal sonography with that of the uterine cavity on saline hysterosonography.
RESULTS: Saline hysterosonography showed abnormalities in 114 patients. Polyps were identified in 53 patients, submucosal leiomyomas in 37 patients, uterine anomalies in two patients, a uterine anomaly and a submucosal leiomyoma in one patient, uterine synechiae in three patients, a synechia and a polyp in one patient, thick endometrial walls in six patients, nondistensible cavities in two patients, and polyps and submucosal leiomyomas in nine patients. Sixteen (14%) of 114 patients showed abnormalities (polyps and submucosal leiomyomas) on saline hysterosonography despite normal-appearing endometria on conventional transvaginal sonography.
CONCLUSION: Conventional transvaginal pelvic sonography does not appear to be a screening procedure of sufficient diagnostic value in the symptomatic patient with abnormal vaginal bleeding. In patients presenting with the chief complaint of abnormal vaginal bleeding, diagnostic evaluation with a saline hysterosonogram may be warranted despite normal findings on a transvaginal pelvic sonogram.