The use of ultrasonography combined with saline infusion of the uterine cavity, called sonohysterography, is under investigation as a tool to evaluate the etiology of abnormal uterine bleeding in reproductive-aged and postmenopausal women. Endometrial biopsy has been widely used to evaluate abnormal uterine bleeding. Recently, transvaginal ultrasonographic measurement of endometrial thickness has been proposed as a screening tool to help physicians decide whether or not to perform endometrial sampling. Focal intracavitary lesions such as polyps and submucous myomas, and atrophy can also be a source of bleeding. Cohen and associates questioned whether intracavitary lesions are prevalent before initiation of hormone replacement therapy (HRT) and if so, whether measurement of endometrial thickness could detect their presence.

A total of 60 postmenopausal women presenting for routine care and considering HRT were evaluated. All women underwent transvaginal ultrasonography in conjunction with sonohysterography, followed by an endometrial biopsy (using a Pipelle aspirator) before HRT was initiated.

In women with an endometrial thickness of less than 5 mm, no neoplasia was detected on Pipelle sampling; 22.7 percent of women with an endometrial thickness greater than 5 mm had simple hyperplasia without atypia. When sonohysterography was performed, cavitary pathology was noted in 36.8 percent of women with an endometrial thickness of less than 5 mm and in 63.6 percent of women with an endometrial thickness of greater than 5 mm, including one patient with Asherman's syndrome.

The size of the intracavitary lesions ranged from 2 to 15 mm. Most of the lesions were not suspected on transvaginal ultrasonography. Transvaginal ultrasonography could not determine if the lesion was predominately intracavitary or intramural. The negative predictive value for an endometrial thickness of less than 5 mm for neoplasia was 100 percent. However, the sensitivity of endometrial thickness measurements in detecting intracavitary pathology was only 50 percent and the specificity was 75 percent. Results of this study demonstrate that sonohysterography was more predictive than endometrial thickness of intracavitary pathology.

It is known that abnormal uterine bleeding is one reason women discontinue HRT. This study demonstrates that lesions commonly discovered in women with abnormal uterine bleeding on HRT can be visualized with sonohysterography before HRT is initiated. The authors suggest the sonohysterography will help identify women with existing intrauterine pathology who may be at increased risk of developing abnormal bleeding on HRT.

The authors conclude that the incidence of intracavitary pathology as detected by sonohysterography is quite high, even in asymptomatic women. The authors are currently evaluating the association between the presence of intrauterine lesions and abnormal uterine bleeding after HRT initiation.

editor's note: This study represents another example of the utility of sonohysterography in the evaluation of abnormal uterine bleeding. Although evaluating every woman before initiation of HRT may be an overly aggressive approach, the results of this study are important in that they revealed that an endometrial thickness of less than 5 mm does not eliminate intrauterine pathology that may be a source of abnormal uterine bleeding. Although transvaginal ultrasonography has become a popular means of evaluating the endometrial “stripe,” many studies lack histologic confirmation relating the association of endometrial thickness on transvaginal ultrasonography and endometrial hyperplasia or carcinoma.—b.a.